Exhibit 2a

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 Page 1 of 108
Infringement Contentions – PayPal’s Android 

U.S. Patent No. 5,991,399 

Claim Analysis 1. A method of securely distributing data comprising: 

PayPal’s mobile software application products and services including by way of “mobile apps” or “Accused Products”) that are specifically developed, used, sold

downloaded onto Android mobile or tablet devices. 

 Venmo (https://play.google.com/store/apps/details?id=com.venmo&hl

 PayPal Mobile Cash: Send and Request Money Fast (https://play.google

accessed on Mar 19, 2020 

 PayPal Here - POS, Credit Card Reader (https://play.google.com/store/a PayPal Business: Send Invoices and Track Sales (https://play.google.com

on Mar 19, 2020 

 PayPal Carica (https://play.google.com/store/apps/details?id=com.payp

PayPal directly infringes and/or continues to knowingly induce Google to infringadvertising, providing, sending, distributing and licensing its mobile applications 

abetting, encouraging, promoting or inviting use thereof. To the extent any steps identified herein are performed by Google, such acts are Google in a joint enterprise in the building and distribution of its mobile apps, ounder the direction and control of PayPal, or acts as agent, or on behalf of PayP

Alternatively, any steps or acts performed by PayPal, are attributable to Google, the distribution of PayPal’s mobile apps through its app store, upon compliance Google in the building and upload of PayPal’s mobile apps, and PayPal induces i

PayPal’s mobile apps.To the extent the preamble is limiting, PayPal distributes data according to the m

In order to build and send the mobile app securely to the Google servers, PayPa

securely distribute its mobile app to PayPal’s customers through the Google app 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Developer Console (https://play.google.com/apps/publish/, Last accessed on M

Google app store, Google Play, as evidenced by the “https” in the URL. Source: https://support.google.com/googleplay/android-developer/answer/611

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
generating an asymmetric key pair 

having a public key and a private key; 

The Court previously construed1 “an asymmetric key pair having a public key anpairs, one of the asymmetric key pairs having the claimed public key and claimecomplementary by performing complementary functions, such as encrypting anAlso relevant to this claim element is the Court’s previous construction of “execcode module” / “tamper resistant key module” to mean “software that is designmodification, and that includes a key for secure communication.” Also relevant to this claim element is the Court’s rejection of limiting “including” Upon information and belief, the method step of “generating an asymmetric keand/or its agents – whose acts are attributable to PayPal (i) because PayPal wor

distribution of its mobile apps, or (ii) because Google distributes and markets Paas agent, or on behalf of PayPal, in the building, marketing and distribution of PaAlternatively, to the extent any portion of this method step is performed by Payparticipation in and the receipt of a benefit, namely, the distribution of PayPal’s 

mandatory procedures and guidelines dictated by Google in the building and up

Google in the building, marketing and distribution of PayPal’s mobile apps. PayPal uploads their mobile apps to Google using a TLS connection – which begithat allows PayPal and Google to exchange cryptographic parameters, including communication including upload of PayPal’s mobile apps to Google servers. A TLS handshake begins with PayPal sending a list of cipher suites supported by the following key exchange algorithms: 

1 See Memorandum Opinion and Order, Document 104 signed by Judge Rodney Gilstrap on 7/21/2016 in re Plano Encryption Techno

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Each of these algorithms necessitates generating one or more asymmetric key pFor RSA and RSA _PSK, a Google server generates an RSA public-private key pai

performing complementary function encrypting and decrypting data. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, Google server generates a

public-private key pair2. PayPal also generates a second Diffie-Hellman public-pr

complementary by performing complementary functions, such as creating and vHellman private key are also complementary by performing complementary funthe Diffie-Hellman key exchange algorithm, PayPal uses Google’s Diffie-Hellman 

compute a premaster secret and thereon a master secret3 for encrypting data. G

Google’s own Diffie-Hellman private key to compute the same premaster secret 

Conversely, Google uses PayPal’s Diffie-Hellman public key combined with Goog

and thereon, a master secret4 for encrypting data. PayPal uses Google’s Diffie-Hkey to compute a premaster secret and thereon a master secret for decrypting eFor DHE_DSS and DH_DSS, Google server generates a DSA public-private key pa

generates a second Diffie-Hellman public-private key pair. The DSA public key ancomplementary functions, such as creating and verifying signatures. The Diffie-Hcomplementary by performing complementary functions, such as encrypting anexchange algorithm, PayPal uses Google’s Diffie-Hellman public key combined wsecret and thereon a master secret5 for encrypting data. Google in turn uses PayHellman private key to compute the same premaster secret and the master secr

2 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellmhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac3 The master secret obtained from the premaster secret may be hashed according to a hashing algorithm also specified in the cipher s

https://tools.ietf.org/html/rfc5246, Sections 6.3, 7.4.9 and 8.1. 4 The master secret obtained from the premaster secret may be hashed according to a hashing algorithm also specified in the cipher s

https://tools.ietf.org/html/rfc5246, Sections 6.3, 7.4.9 and 8.1. 5 The master secret obtained from the premaster secret may be hashed according to a hashing algorithm also specified in the cipher s

https://tools.ietf.org/html/rfc5246, Sections 6.3, 7.4.9 and 8.1. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
uses PayPal’s Diffie-Hellman public key combined with Google’s own Diffie-Hellm

master secret6 for encrypting data. PayPal uses Google’s Diffie-Hellman public k

compute a premaster secret and thereon a master secret for decrypting encryptFor ECDH_ECDSA and ECDHE_ECDSA, a Google server generates an ECDSA publ

PayPal also generates a second Diffie-Hellman public-private key pair. The ECDS

performing complementary functions, such as creating and verifying signatures. also complementary by performing complementary functions, such as encryptin

exchange algorithm, PayPal uses Google’s Diffie-Hellman public key combined wsecret and thereon a master secret7 for encrypting data. Google in turn uses PayHellman private key to compute the same premaster secret and the master secr

uses PayPal’s Diffie-Hellman public key combined with Google’s own Diffie-Hellmmaster secret8 for encrypting data. PayPal uses Google’s Diffie-Hellman public k

compute a premaster secret and thereon a master secret for decrypting encrypt

6 The master secret obtained from the premaster secret may be hashed according to a hashing algorithm also specified in the cipher s

https://tools.ietf.org/html/rfc5246, Sections 6.3, 7.4.9 and 8.1. 7 The master secret obtained from the premaster secret may be hashed according to a hashing algorithm also specified in the cipher s

https://tools.ietf.org/html/rfc5246, Sections 6.3, 7.4.9 and 8.1. 8 The master secret obtained from the premaster secret may be hashed according to a hashing algorithm also specified in the cipher s

https://tools.ietf.org/html/rfc5246, Sections 6.3, 7.4.9 and 8.1. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2020

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 50-51, Last accessed on Mar 19, 202

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

In addition, PayPal and/or Google also generate additional asymmetric key pairs communications during the operation of the mobile app. Thus, at least one asymmetric key pair is generated having the claimed public ke

that the mobile app code and metadata can be sent securely to the Google serv

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
pair used to digitally sign the app) is complementary as described below by perf

data and/or creating and verifying signatures. As described in greater detail belsecurely upload the mobile app onto the Google servers by SSL/TLS when buildi

claimed asymmetric key pair and the encrypted predetermined data that has be

encrypting predetermined data with the generated public key; 

Upon information and belief, the method step of “encrypting predetermined daagents. To the extent any portion of the method step is performed by Google and/or its 

together with Google in a joint enterprise in the building and distribution of its mmobile apps under the direction and control of PayPal, or acts as agent, or on be

mobile apps. When PayPal uploads its mobile apps to Google, it connects to Google Play Deve

TLS handshake procedure which uses asymmetric key encryption and necessitatnegotiates with Google a cipher suite and the key exchange algorithm that will b

 The cryptographic parameters of the session state are produced by the 

 TLS Handshake Protocol, which operates on top of the TLS record  layer. When a TLS client and server first start communicating, they  agree on a protocol version, select cryptographic algorithms,  optionally authenticate each other, and use public-key encryption  techniques to generate shared secrets.  The TLS Handshake Protocol involves the following steps: 

 - Exchange hello messages to agree on algorithms, exchange random  values, and check for session resumption.  - Exchange the necessary cryptographic parameters to allow the 

 client and server to agree on a premaster secret.  - Exchange certificates and cryptographic information to allow the  client and server to authenticate themselves.

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
 - Generate a master secret from the premaster secret and exchanged 

 random values.  - Provide security parameters to the record layer.  - Allow the client and server to verify that their peer has 

 calculated the same security parameters and that the handshake  occurred without tampering by an attacker. 

Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

The actual key exchange uses up to four messages: the server 

 Certificate, the ServerKeyExchange, the client Certificate, and the  ClientKeyExchange. New key exchange methods can be created by 

 specifying a format for these messages and by defining the use of the  messages to allow the client and server to agree upon a shared  secret. This secret MUST be quite long; currently defined key  exchange methods exchange secrets that range from 46 bytes upwards.  Following the hello messages, the server will send its certificate in  a Certificate message if it is to be authenticated. Additionally, a  ServerKeyExchange message may be sent, if it is required (e.g., if  the server has no certificate, or if its certificate is for signing  only). If the server is authenticated, it may request a certificate  from the client, if that is appropriate to the cipher suite selected.  Next, the server will send the ServerHelloDone message, indicating  that the hello-message phase of the handshake is complete. The  server will then wait for a client response. If the server has sent  a CertificateRequest message, the client MUST send the Certificate  message. The ClientKeyExchange message is now sent, and the content  of that message will depend on the public key algorithm selected  between the ClientHello and the ServerHello. If the client has sent  a certificate with signing ability, a digitally-signed 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
 CertificateVerify message is sent to explicitly verify possession of 

 the private key in the certificate. 

Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

The TLS Handshaking Protocols 

 TLS has three subprotocols that are used to allow peers to agree upon  security parameters for the record layer, to authenticate themselves,  to instantiate negotiated security parameters, and to report error  conditions to each other.  The Handshake Protocol is responsible for negotiating a session,  which consists of the following items:  session identifier  An arbitrary byte sequence chosen by the server to identify an  active or resumable session state.  peer certificate  X509v3 [PKIX] certificate of the peer. This element of the state 

 may be null.  compression method  The algorithm used to compress data prior to encryption.  cipher spec  Specifies the pseudorandom function (PRF) used to generate keying  material, the bulk data encryption algorithm (such as null, AES,  etc.) and the MAC algorithm (such as HMAC-SHA1). It also defines  cryptographic attributes such as the mac_length. (See Appendix

A.6 for formal definition.) 

 master secret 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
 48-byte secret shared between the client and server. 

 is resumable  A flag indicating whether the session can be used to initiate new  connections.  These items are then used to create security parameters for use by  the record layer when protecting application data. Many connections  can be instantiated using the same session through the resumption  feature of the TLS Handshake Protocol. 

Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

As explained above, PayPal and Google negotiate a key exchange algorithm from 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

For each of the above key exchange algorithms, Google and/or PayPal encrypts For RSA and RSA _PSK, PayPal encrypts a random premaster secret with Google

Google. Google decrypts the premaster secret with its matched RSA private key

master secret which is then used by both PayPal and Google to encrypt all subse

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
when any of RSA and RSA _PSK algorithms are chosen during a TLS handshake, 

the generated public key (i.e. Google’s RSA public key). For the other key exchange algorithms, namely Diffie-Hellman based algorithms 

ECDH_RSA, ECDH_ECDSA and ECDHE_ECDSA, PayPal sends its Diffie-Hellman pu

to PayPal. PayPal then uses Google’s Diffie-Hellman public key combined with Psecret. Google in turn uses PayPal’s Diffie-Hellman public key combined with Go

premaster secret. PayPal and Google both use the premaster secret to compute 

encrypt all subsequent communications between PayPal and Google. Therefore, when any of the Diffie-Hellman based key exchange algorithms are ci.e. all communication with Google subsequent to the TLS handshake, including 

information such as name, category, screenshots and description related to Pay

Hellman public key, since the master secret used to encrypt the predetermined PayPal’s Diffie-Hellman private key11. 

Similarly, when any of the Diffie-Hellman based key exchange algorithms are ch

i.e. all communication with Google subsequent to the TLS handshake, including Developer Console website and forms that PayPal uses for uploading its mobile 

Diffie-Hellman public key, since the master secret used to encrypt the predeterm

Google’s Diffie-Hellman private key12. 

and building an executable tamper 

Relevant to this claim element is the Court’s previous construction13 of “executa

code module” / “tamper resistant key module” to mean “software that is design

9 For Diffie-Hellman (DH) based algorithms such as DH_RSA, DHE_RSA, ECDH_RSA, ECDHE_RSA, DH_DSS, DHE_DSS, ECDH_ECDSA and Diffie-Hellman public key and encrypts the hash with their RSA/DSA/ECDSA private key (i.e. signing the message). Google then sends t

can authenticate the Google server by decrypting the hash using Google’s public key and matching the decryption result to a hash of t

PayPal knows that the message originated from Google and not from a malicious third party. 10 The master secret obtained from the premaster secret may be hashed according to a hashing algorithm also specified in the cipher https://tools.ietf.org/html/rfc5246, Sections 6.3, 7.4.9 and 8.1. 11 See, for example, https://tools.ietf.org/html/rfc2631, Page 2, Last accessed on Mar 19, 2020 12 Id. 13 See Memorandum Opinion and Order, Document 104 signed by Judge Rodney Gilstrap on 7/21/2016 in re Plano Encryption Techno

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
resistant key module identified for a 

selected program, the executable tamper resistant key module including the generated private key and the encrypted predetermined data. 

modification, and that includes a key for secure communication.” Also relevant “including” to compiling14. The method step of “building an executable tamper resistant key module identi

module including the generated private key and the encrypted predetermined d

To the extent any portion of the method step is performed by Google and/or its 

together with Google in a joint enterprise in the building and distribution of its mmobile apps under the direction and control of PayPal, or acts as agent, or on be

mobile apps. Building of an “executable tamper resistant code module” (that is, the mobile aasymmetric key pairs: (1) An asymmetric key pair must be included in order to send the mobile ap

(2) An asymmetric key pair must be included by PayPal in order to digitally 

mobile app has not been changed with the public key for Android compatible mThe asymmetric key pair that is included to digitally sign the mobile app is differ

securely upload the mobile app to the Google servers for distribution on the GoThus, at least one asymmetric key pair is included having the claimed public key 

the mobile app code can be sent uploaded to the Google servers using SSL/TLS ppair used to digitally sign the app) is complementary as described below by perfdata and/or creating and verifying signatures. As described in greater detail belsecurely upload the mobile app onto the Google servers by SSL/TLS when buildi

claimed asymmetric key pair(s) and the encrypted predetermined data. PayPal uploads their mobile apps to Google using a TLS connection – which begi

that allows PayPal and Google to exchange cryptographic parameters, including communication including upload of PayPal’s mobile apps to Google servers. 

14 Also relevant is the Court’s construction of “an asymmetric key pair having a public key and a private key” in claims 1, 9 and 10 to m

having the claimed public key and claimed private key, the asymmetric keys of an asymmetric key pair being complementary by perfocreating and verifying signatures.” 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
A TLS handshake begins with PayPal sending a list of cipher suites supported by 

the following key exchange algorithms: 

Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

For each of the key exchange algorithms, PayPal and/or Google build an executa

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
key and the encrypted predetermined data. 

For RSA and RSA _PSK, the executable tamper resistant key module includes en

it would be impossible for PayPal to send its mobile app to Google using SSL/TLS executable tamper resistant key module also includes: 

1. Google’s RSA private key corresponding to Google’s RSA public key used 

2. PayPal’s private key used to code-sign the mobile app. 

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, the executable tamper res

communication with Google subsequent to the TLS handshake, including at leas

information such as name, category, screenshots and description related to Pay

includes: 

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s RSA private key used to sign the message containing Google’s 4. PayPal’s private key used to code-sign the mobile app. 

For DHE_DSS and DH_DSS, the executable tamper resistant key module includesubsequent to the TLS handshake, including at least the executable compiled cocategory, screenshots and description related to PayPal’s mobile apps). The exe

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s DSA private key used to sign the message containing Google’s 

4. PayPal’s private key used to code-sign the mobile app. 

For ECDH_ECDSA and ECDHE_ECDSA, the executable tamper resistant key mod

with Google subsequent to the TLS handshake, including at least the executable 

name, category, screenshots and description related to PayPal’s mobile apps). T

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s ECDSA private key used to sign the message containing Google

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
4. PayPal’s private key used to code-sign the mobile app. 

PayPal builds an executable tamper resistant key module identified for a selectemobile app, which is an executable tamper resistant key module, as explained in 

program resident on a remote system, namely the Android operating system on The mobile app comprises an executable tamper resistant key module that is iddescribed above and the encrypted predetermined data encrypted with the claithat it can be made available for download from Google servers onto devices coPayPal. An asymmetric key pair is used not only to upload the binary code files fthe metadata for the app, such as title, screenshots, and other resources or infoincluded during the upload process so that the mobile app can be identified by p

PayPal’s mobile app is each an executable tamper resistant key module because 

operating system as well as other applications or programs installed on a user’s 

and modification, as explained below; and because in building PayPal mobile ap

generated private key and the encrypted predetermined data including by way generated public key when the mobile app is securely uploaded onto the Google The tamper resistant key module includes several keys “used for secure commufollowing: For RSA and RSA _PSK: 

1. Google’s RSA private key corresponding to Google’s RSA public key used 

2. PayPal’s private key used to code-sign the mobile app. 3. Symmetric key used for uploading the mobile app to Google subsequen4. Asymmetric keys and symmetric keys used for TLS communications duri

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA: 

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s RSA private key used to sign the message containing Google’s 

15 See, e.g., https://developer.android.com/studio/publish/index.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
4. PayPal’s private key used to code-sign the mobile app. 

5. Shared master secret key used for uploading the mobile app to Google s6. Asymmetric keys and symmetric keys used for TLS communications duri

For DHE_DSS and DH_DSS: 

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s DSA private key used to sign the message containing Google’s 

4. PayPal’s private key used to code-sign the mobile app. 5. Shared master secret key used for uploading the mobile app to Google s6. Asymmetric keys and symmetric keys used for TLS communications duri

For ECDH_ECDSA and ECDHE_ECDSA: 

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s ECDSA private key used to sign the message containing Google

4. PayPal’s private key used to code-sign the mobile app. 5. Shared master secret key used for uploading the mobile app to Google s6. Asymmetric keys and symmetric keys used for TLS communications duri

PayPal’s mobile apps are tamper resistant, resistant to observation and modifica

1. Resistant to Observation Because App Source Code Is Compiled Before 

PayPal mobile apps are resistant to observation, at least in part, since PayPal co

Google – and uploads the binary output of the compilation process rather than 

See, Android Studio Users Guide, “Prepare for Release” stating “To release your 

users can install and run on their Android-powered devices. The release-ready p

compiled source code, resources, manifest file, and so on — and it is built using 

16 See, e.g., https://developer.android.com/studio/build/index.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
release-ready APK file is signed with your own certificate and it is optimized wit

https://developer.android.com/studio/publish/preparing.html, Last accessed on 

2. Resistant to Observation Because Upload To Google Is Over SSL/TLS 

PayPal’s mobile apps are made further resistant to observation, at least in part, 

of the building process. Android Developer Console (https://play.google.com/ap

communications when uploading PayPal’s apps, as evidenced by the “https” in tthe code from being observed in transit from the code developer to Google. The secure upload process starts with a TLS handshake procedure which uses as

asymmetric key pair. Specifically, PayPal negotiates with Google the cipher suite 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

For each of the above key exchange algorithms, Google and/or PayPal encrypts master secret, rendering the communication resistant to observation during traFor RSA and RSA _PSK, PayPal encrypts a random premaster secret with Google

Google. Google decrypts the premaster secret with its matched RSA private key

master secret which is then used by both PayPal and Google to encrypt all subse

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
For the other key exchange algorithms, namely Diffie-Hellman based algorithms 

ECDH_RSA, ECDH_ECDSA and ECDHE_ECDSA, PayPal sends its Diffie-Hellman pu

to PayPal. PayPal then uses Google’s Diffie-Hellman public key combined with Psecret. Google in turn uses PayPal’s Diffie-Hellman public key combined with Go

premaster secret. PayPal and Google both use the premaster secret to compute 

encrypt all subsequent communications between PayPal and Google. 

3. Resistant to Modification Because App Binary Is Code Signed 

The mobile app code is made resistant to modification, at least in part, because must sign the mobile app submission with his/her asymmetric developer key th

impersonator18. 

Android requires that the user generates an asymmetric key all apps be d

uses this certificate to identify the author of an app Source: https://developer.android.com/studio/publish/app-signing.html

A public-key certificate, also known as a digital certificate or an identity c

as some other metadata identifying the owner of the key (for example, ncorresponding private key. When you sign an APK, the signing tool attaches the public-key certificate that uniquely associates the APK to you and your corresponding private kauthentic and come from the original author. 

A keystore is a binary file that contains one or more private keys. When y

generate a new keystore and private key or use a keystore and private keSource: https://developer.android.com/studio/publish/app-signing.html

17 For Diffie-Hellman (DH) based algorithms such as DH_RSA, DHE_RSA, ECDH_RSA, ECDHE_RSA, DH_DSS, DHE_DSS, ECDH_ECDSA and 

Diffie-Hellman public key and encrypts the hash with their RSA/DSA/ECDSA private key (i.e. signing the message). Google then sends t

can authenticate the Google server by decrypting the hash using Google’s public key and matching the decryption result to a hash of tPayPal knows that the message originated from Google and not from a malicious third party. 18 See, e.g., https://developer.android.com/tools/publishing/app-signing.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171107004101/https://develope

accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171107004101/https://develope

accessed on Mar 19, 2020Source: http://web.archive.org/web/20171107004101/https://developeaccessed on Mar 19, 2020

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
PayPal complies with Google’s instructions on code signing as shown by PayPal’

files CERT.SF and CERT.RSA in PayPal’s Android apps which are generated during 

Source: Contents of Venmo (https://play.google.com/store/apps/details?id=com

Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: Contents of Venmo (https://play.google.com/store/apps/details?id=com

Mar 19, 2020 Asymmetrical key cryptography and hashing algorithms are used to create the uis used to sign the resources in an application package, including the compiled cthe digital code signing is used to code sign the app. This private key is included key of the claimed generated asymmetric key pair because it does not match ththe court’s construction. Hashes are created for every resource in the application package with the help oprevent unauthorized changes. The hashes are encrypted with a private key. Aft

created. By signing the app binary with a digital signature, PayPal’s mobile apps are tamp

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
verify that the application is being distributed by trusted source (i.e. PayPal) and 

can be verified by the corresponding public key generated as part of the pair. Th

Accordingly PayPal’s Android mobile apps establish SSL/TLS communications witinvolving asymmetric key encryption. SSL/TLS ensures secure communication an

2. The method of claim 1, wherein the program is on a remote system and further comprising sending the executable tamper resistant key module to the remote system. 

PayPal’s mobile software application products and services including by way of “mobile apps” or “Accused Products”) that are specifically developed, used, sold

downloaded onto Android mobile or tablet devices. 

 Venmo (https://play.google.com/store/apps/details?id=com.venmo&hl

 PayPal Mobile Cash: Send and Request Money Fast (https://play.google

accessed on Mar 19, 2020 

 PayPal Here - POS, Credit Card Reader (https://play.google.com/store/a PayPal Business: Send Invoices and Track Sales (https://play.google.com

on Mar 19, 2020 

 PayPal Carica (https://play.google.com/store/apps/details?id=com.payp

PayPal directly infringes and/or continues to knowingly induce Google to infringadvertising, providing, sending, distributing and licensing its mobile applications 

abetting, encouraging, promoting or inviting use thereof. Upon information and belief, the method step of sending the executable tampe

and/or its agents – whose acts are attributable to PayPal (i) because PayPal wor

distribution of its mobile apps, or (ii) because Google distributes and markets Paas agent, or on behalf of PayPal, in the building, marketing and distribution of PaAlternatively, to the extent any portion of this method step is performed by Payparticipation in and the receipt of a benefit, namely, the distribution of PayPal’s 

mandatory procedures and guidelines dictated by Google in the building and up

Google in the building, marketing and distribution of PayPal’s mobile apps. PayPal’s mobile apps are sent or downloaded from Google servers and are execWhen a user accesses Google Play Store – and requests to download PayPal app

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Google servers to the remote device(s). 

Further, the step of “sending” PayPal mobile apps to the remote system occurs 

apps, to the extent required by the claims, also includes a private key and prede

above. In particular, PayPal mobile apps sent to users’ remote devices are tamper resis

1. Resistant to Observation Because App is Downloaded in Compiled For

PayPal mobile apps are resistant to observation, at least in part, since PayPal coGoogle – and uploads the binary output of the compilation process rather than 

compiled source code from Google rather than the source code itself19.See, Android Studio Users Guide, “Prepare for Release” stating “To release your users can install and run on their Android-powered devices. The release-ready p

compiled source code, resources, manifest file, and so on — and it is built using release-ready APK file is signed with your own certificate and it is optimized wit

https://developer.android.com/studio/publish/preparing.html, Last accessed on 

2. Resistant to Observation Because Download from Google Is Over SSL/T

PayPal’s mobile apps are made further resistant to observation, at least in part, from Google servers. PayPal app users establish SSL/TLS communications with Phttps://play.google.com/store/apps/details?id=com.venmo&hl=en_US for Venmas evidenced by the “https” in the URL. Sending the mobile app code by SSL/TLS Google to the user’s remote system. The secure download process starts with a TLS handshake procedure which uses one asymmetric key pair. Specifically, user’s remote device negotiates with Goofor the handshake.: 

19 See, e.g., https://developer.android.com/studio/build/index.html

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Each of these algorithms necessitates generating one or more asymmetric key pencrypting the mobile app download. For RSA and RSA _PSK, Google server generates an RSA public-private key pair. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, Google server generates a

key pair20. The user’s remote device also generates a second Diffie-Hellman pubFor DHE_DSS and DH_DSS, Google server generates a DSA public-private key pa

remote device also generates a second Diffie-Hellman public-private key pair. For ECDH_ECDSA and ECDHE_ECDSA, Google server generates an ECDSA public

The user’s remote device also generates a second Diffie-Hellman public-private 

20 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 50-51, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

The generated asymmetric key pairs are then used to compute a shared master 

that it is resistant to observation during transit.For RSA and RSA _PSK, the RSA public-private key pair is used to encrypt a rand

user’s remote device to compute a master secret. Google uses the master secre

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
decrypt the downloaded mobile app according to the TLS protocol. 

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, Google server generates a

key pair21. The user’s remote device also generates a second Diffie-Hellman puband the user’s Diffie-Hellman public key to compute a premaster secret, and sub

the user’s Diffie-Hellman private key and Google’s Diffie-Hellman public key to c

secret that Google uses to encrypt the mobile app and the user’s remote device protocol. For DHE_DSS and DH_DSS, Google server generates a DSA public-private key pa

remote device also generates a second Diffie-Hellman public-private key pair. G

Hellman public key to compute a premaster secret, and subsequently compute 

Hellman private key and Google’s Diffie-Hellman public key to compute the samuses to encrypt the mobile app and the user’s remote device uses to decrypt the For ECDH_ECDSA and ECDHE_ECDSA, Google server generates an ECDSA public

The user’s remote device also generates a second Diffie-Hellman public-private user’s Diffie-Hellman public key to compute a premaster secret, and subsequenDiffie-Hellman private key and Google’s Diffie-Hellman public key to compute th

Google uses to encrypt the mobile app and the user’s remote device uses to dec

3. Resistant to Modification Because Mobile App is Code Signed 

The downloaded mobile app code is resistant to modification, at least in part, beallows users’ remote systems to verify that the downloaded app binary is authe

21 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
dictates that each developer must sign the mobile app submission with his/her 

modified by a third party impersonator22. 

Android requires that the user generates an asymmetric key all apps be d

uses this certificate to identify the author of an app Source: https://developer.android.com/studio/publish/app-signing.html

A public-key certificate, also known as a digital certificate or an identity c

as some other metadata identifying the owner of the key (for example, ncorresponding private key. When you sign an APK, the signing tool attaches the public-key certificate that uniquely associates the APK to you and your corresponding private kauthentic and come from the original author. 

A keystore is a binary file that contains one or more private keys. When y

generate a new keystore and private key or use a keystore and private keSource: https://developer.android.com/studio/publish/app-signing.html

PayPal complies with Google’s instructions on code signing as shown by PayPal’files CERT.SF and CERT.RSA in PayPal’s Android mobile apps which are generate

22 See, e.g., https://developer.android.com/tools/publishing/app-signing.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: Contents of Venmo (https://play.google.com/store/apps/details?id=com

Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: Contents of Venmo (https://play.google.com/store/apps/details?id=com

Mar 19, 2020 By signing the app binary with a digital signature, PayPal’s mobile apps are tampverify that the application is being distributed by trusted source (i.e. PayPal) and can be verified by the corresponding public key generated as part of the pair. ThAccordingly PayPal’s Android mobile apps establish SSL/TLS communications witinvolving asymmetric key encryption. SSL/TLS ensures secure communication an

4. Resistant to Observation Because Mobile App is Stored on Remote Sys

The mobile app is made further resistant to observation because when downloa

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
encrypted form. Android implements disk encryption for encrypting the operati

which further renders PayPal app resistant to observation23. 

5. Resistant to Observation Because Mobile App Securely Communicates 

PayPal’s mobile apps are made further resistant to observation, at least in part, 

during operation. PayPal app users establish SSL/TLS communications with Paynecessary to keep source code as well as user identity and activity from being oversa. The secure communications process starts with a TLS handshake procedure whi

least one asymmetric key pair. Specifically, user’s remote device negotiates with 

will be used for the handshake. 

23 See, e.g., https://source.android.com/security/encryption/, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Each of these algorithms necessitates generating one or more asymmetric key pencrypting communication between PayPal and user’s remote device. For RSA and RSA _PSK, PayPal server generates an RSA public-private key pair. 

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, PayPal server generates an 

key pair24. The user’s remote device also generates a second Diffie-Hellman pub

24 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
For DHE_DSS and DH_DSS, PayPal server generates a DSA public-private key pa

remote device also generates a second Diffie-Hellman public-private key pair. For ECDH_ECDSA and ECDHE_ECDSA, PayPal server generates an ECDSA public-The user’s remote device also generates a second Diffie-Hellman public-private 

http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2020

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 50-51, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

The generated asymmetric key pairs are then used to compute a shared master 

between PayPal and the user’s remote device so that they are resistant to obserFor RSA and RSA _PSK, the RSA public-private key pair is used to encrypt a rand

user’s remote device to compute a master secret. PayPal and the user’s remote 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
communication messages. 

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, PayPal server generates an 

key pair25. The user’s remote device also generates a second Diffie-Hellman puband the user’s Diffie-Hellman public key to compute a premaster secret, and subthe user’s Diffie-Hellman private key and Google’s Diffie-Hellman public key to c

secret for encrypting and decrypting communication messages. 

For DHE_DSS and DH_DSS, PayPal server generates a DSA public-private key paremote device also generates a second Diffie-Hellman public-private key pair. P

Hellman public key to compute a premaster secret, and subsequently compute 

Hellman private key and Google’s Diffie-Hellman public key to compute the sam

encrypting and decrypting communication messages. For ECDH_ECDSA and ECDHE_ECDSA, PayPal server generates an ECDSA public-The user’s remote device also generates a second Diffie-Hellman public-private 

user’s Diffie-Hellman public key to compute a premaster secret, and subsequenDiffie-Hellman private key and Google’s Diffie-Hellman public key to compute th

encrypting and decrypting communication messages. 

9. The method of claim 1, wherein building the executable tamper resistant code module comprises generating an integrity verification kernel. 

PayPal’s mobile software application products and services including by way of “mobile apps” or “Accused Products”) that are specifically developed, used, sold

downloaded onto Android mobile or tablet devices. 

 Venmo (https://play.google.com/store/apps/details?id=com.venmo&hl

 PayPal Mobile Cash: Send and Request Money Fast (https://play.google

accessed on Mar 19, 2020 

25 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
 PayPal Here - POS, Credit Card Reader (https://play.google.com/store/a

 PayPal Business: Send Invoices and Track Sales (https://play.google.com

on Mar 19, 2020 

 PayPal Carica (https://play.google.com/store/apps/details?id=com.payp

PayPal directly infringes and/or continues to knowingly induce Google to infringadvertising, providing, sending, distributing and licensing its mobile applications 

abetting, encouraging, promoting or inviting use thereof. Upon information and belief, the method step of generating an integrity verifica

are attributable to PayPal (i) because PayPal works together with Google in a joibecause Google distributes and markets PayPal’s mobile apps under the directio

the building, marketing and distribution of PayPal’s mobile apps. Alternatively, to the extent any portion of this method step is performed by Payparticipation in and the receipt of a benefit, namely, the distribution of PayPal’s 

mandatory procedures and guidelines dictated by Google in the building and up

Google in the building, marketing and distribution of PayPal’s mobile apps. The Court construed “integrity verification kernel” to mean “software that verifand that is resistant to observation and modification.” When a mobile app is deployed on device, a hash algorithm is used to compute 

hashes in the hash manifest. Then, the hashes from the hash manifest are compmatch, the digital signature is invalid and the application does not launch. Thus, 

image for the app, and this digital signature is supplied so that the mobile app c

The code for Android used to validate the digitally signed mobile app code is itse

Further, Android implements disk encryption for encrypting the operating systewhich renders the code for validating the digitally signed mobile app binary furt

26 See, e.g., https://developer.android.com/studio/publish/app-signing.html, Last accessed on Mar 19, 2020 27 See, e.g., https://source.android.com/security/encryption/, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Further Android implements a secure boot functionality that verifies the operat

when the mobile device is powered on. If this verification fails, i.e. if the operati

not launch28. Thus, the software that verifies that a program image corresponds 

modification. 

28 See, e.g., https://source.android.com/security/verifiedboot/ and http://www.zdnet.com/article/google-now-requires-full-device-e

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171208043438/https://source.android.c

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20170912153704/https://source.android.c

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Further Android implements a secure boot functionality that verifies the operat

when the mobile device is powered on. If this verification fails, i.e. if the operati

not launch. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171201215912/https://source.android.c

This verified boot became mandatory for Android 6.0 or later: https://source.android.com/compatibility/6.0/android-6.0-cdd, Last accessed o

10. The method of claim 9, wherein generating an integrity verification kernel comprises accessing an asymmetric public key of a predetermined asymmetric key pair 

PayPal’s mobile software application products and services including by way of “mobile apps” or “Accused Products”) that are specifically developed, used, sold

downloaded onto Android mobile or tablet devices. 

 Venmo (https://play.google.com/store/apps/details?id=com.venmo&hl

29 See also http://www.tomshardware.com/news/marshmallow-encryption-fingerprints-verified-boot,30369.html, Last accessed on Mhttp://www.zdnet.com/article/google-now-requires-full-device-encryption-on-new-android-6-0-devices/, Last accessed on Mar 19, 2http://www.androidauthority.com/new-google-oem-marshmallow-requirements-650266/, Last accessed on Mar 19, 2020 https://www.linuxsecrets.com/elinux-wiki/images/b/b2/Android_Verified_Boot.pdf, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
associated with a manifest of the 

program signed by an asymmetric private key of the predetermined asymmetric key pair, producing integrity verification kernel code with the asymmetric public key for verifying the signed manifest of the program and combining manifest parser generator code and the integrity verification kernel code to produce the integrity verification kernel. 

 PayPal Mobile Cash: Send and Request Money Fast (https://play.google

accessed on Mar 19, 2020 

 PayPal Here - POS, Credit Card Reader (https://play.google.com/store/a PayPal Business: Send Invoices and Track Sales (https://play.google.com

on Mar 19, 2020 

 PayPal Carica (https://play.google.com/store/apps/details?id=com.payp

PayPal directly infringes and/or continues to knowingly induce Google to infringadvertising, providing, sending, distributing and licensing its mobile applications 

abetting, encouraging, promoting or inviting use thereof. Upon information and belief, the method step of accessing an asymmetric publi

manifest of the program signed by an asymmetric private key of the predetermiwith the asymmetric public key for verifying the signed manifest of the program 

verification kernel code to produce the integrity verification kernel is performed (i) because PayPal works together with Google in a joint enterprise in the buildindistributes and markets PayPal’s mobile apps under the direction and control of marketing and distribution of PayPal’s mobile apps.Alternatively, to the extent any portion of this method step is performed by Payparticipation in and the receipt of a benefit, namely, the distribution of PayPal’s 

mandatory procedures and guidelines dictated by Google in the building and up

Google in the building, marketing and distribution of PayPal’s mobile apps. The Court previously construed30 “integrity verification kernel” to mean “softwa

digital signature and that is resistant to observation and modification” and “manverification kernel’s entry code, generator code, accumulator code, and other coAndroid implements a secure boot functionality that verifies the operating syste

the mobile device is powered on. If this verification fails, i.e. if the operating sys

the mobile apps installed on the device, does not launch. Thus every time the daccessing an asymmetric public key of a predetermined asymmetric key pair ass

30 See Memorandum Opinion and Order, Document 104 signed by Judge Rodney Gilstrap on 7/21/2016 in re Plano Encryption Techno

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
corresponding asymmetric private key by Google. This integrity verification kern

parses a manifest associated with the operating system and code that verifies th

and has not been maliciously modified. Further, the software that performs the above verification is stored in a compileAdditionally, the software is digitally signed by Google with their asymmetric pr

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171201215912/https://source.android.c

This verified boot became mandatory for Android 6.0 or later: https://source.android.com/compatibility/6.0/android-6.0-cdd, Last accessed o

31 See also http://www.tomshardware.com/news/marshmallow-encryption-fingerprints-verified-boot,30369.html, Last accessed on Mhttp://www.zdnet.com/article/google-now-requires-full-device-encryption-on-new-android-6-0-devices/, Last accessed on Mar 19, 2http://www.androidauthority.com/new-google-oem-marshmallow-requirements-650266/, Last accessed on Mar 19, 2020 https://www.linuxsecrets.com/elinux-wiki/images/b/b2/Android_Verified_Boot.pdf, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171208043438/https://source.android.c

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20170912153704/https://source.android.c

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://web.archive.org/web/20171203224317/https://source.android

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://web.archive.org/web/20170912190232/https://source.android

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
11. The method of claim 10, wherein 

the program comprises a trusted player and the method further comprises building a manifest for the trusted player, signing the manifest with the asymmetric private key of the predetermined asymmetric key pair, and storing the asymmetric public key of the predetermined asymmetric key pair. 

PayPal’s mobile software application products and services including by way of “mobile apps” or “Accused Products”) that are specifically developed, used, sold

downloaded onto Android mobile or tablet devices. 

 Venmo (https://play.google.com/store/apps/details?id=com.venmo&hl

 PayPal Mobile Cash: Send and Request Money Fast (https://play.google

accessed on Mar 19, 2020 

 PayPal Here - POS, Credit Card Reader (https://play.google.com/store/a PayPal Business: Send Invoices and Track Sales (https://play.google.com

on Mar 19, 2020 

 PayPal Carica (https://play.google.com/store/apps/details?id=com.payp

PayPal directly infringes and/or continues to knowingly induce Google to infringadvertising, providing, sending, distributing and licensing its mobile applications 

abetting, encouraging, promoting or inviting use thereof. Upon information and belief, the method step of building a manifest for the tru

the predetermined asymmetric key pair, and storing the asymmetric public key 

and/or its agents – whose acts are attributable to PayPal (i) because PayPal wor

distribution of its mobile apps, or (ii) because Google distributes and markets Paas agent, or on behalf of PayPal, in the building, marketing and distribution of Pa

Alternatively, to the extent any portion of this method step is performed by Payparticipation in and the receipt of a benefit, namely, the distribution of PayPal’s 

mandatory procedures and guidelines dictated by Google in the building and up

Google in the building, marketing and distribution of PayPal’s mobile apps. As explained in claim 10, Android implements a secure boot functionality that v

signed mobile apps, when the mobile device is powered on. If this verification fa

operating system, along with the mobile apps installed on the device, does not l

system on a device before the device is sold to a user, Google builds a manifest the manifest with their asymmetric private key and storing the corresponding a

operating system can be verified during device restart. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171201215912/https://source.android.c

This verified boot became mandatory for Android 6.0 or later: https://source.android.com/compatibility/6.0/android-6.0-cdd , Last accessed o

34. A method of securely distributing data encrypted by a public key of an asymmetric key pair comprising: 

PayPal’s mobile software application products and services including by way of “mobile apps” or “Accused Products”) that are specifically developed, used, sold

downloaded onto Android mobile or tablet devices. 

32 See also http://www.tomshardware.com/news/marshmallow-encryption-fingerprints-verified-boot,30369.html, Last accessed on Mhttp://www.zdnet.com/article/google-now-requires-full-device-encryption-on-new-android-6-0-devices/, Last accessed on Mar 19, 2http://www.androidauthority.com/new-google-oem-marshmallow-requirements-650266/, Last accessed on Mar 19, 2020 https://www.linuxsecrets.com/elinux-wiki/images/b/b2/Android_Verified_Boot.pdf, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
 Venmo (https://play.google.com/store/apps/details?id=com.venmo&hl

 PayPal Mobile Cash: Send and Request Money Fast (https://play.google

accessed on Mar 19, 2020 

 PayPal Here - POS, Credit Card Reader (https://play.google.com/store/a PayPal Business: Send Invoices and Track Sales (https://play.google.com

on Mar 19, 2020 

 PayPal Carica (https://play.google.com/store/apps/details?id=com.payp

PayPal directly infringes and/or continues to knowingly induce Google to infringadvertising, providing, sending, distributing and licensing its mobile applications 

abetting, encouraging, promoting or inviting use thereof. To the extent any steps identified herein are performed by Google, such acts are Google in a joint enterprise in the building and distribution of its mobile apps, ounder the direction and control of PayPal, or acts as agent, or on behalf of PayP

Alternatively, any steps or acts performed by PayPal, are attributable to Google, the distribution of PayPal’s mobile apps through its app store, upon compliance Google in the building and upload of PayPal’s mobile apps, and PayPal induces i

PayPal’s mobile apps.To the extent the preamble is limiting, PayPal distributes data according to the m

In order to build and send the mobile app securely to the Google servers, PayPa

securely distribute its mobile app to PayPal’s customers through the Google Pla(https://play.google.com/apps/publish/, Last accessed on Mar 19, 2020) establi

evidenced by the “https” in the URL. That process necessarily uses the public keto create a symmetric key for secure communications. 

building an executable tamper resistant key module identified for a 

Relevant to this claim element is the Court’s previous construction33 of “executa

code module” / “tamper resistant key module” to mean “software that is design

33 See Memorandum Opinion and Order, Document 104 signed by Judge Rodney Gilstrap on 7/21/2016 in re Plano Encryption Techno

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
selected program resident on a 

remote system, the executable tamper resistant key module including a private key of the asymmetric key pair and the encrypted data; and 

modification, and that includes a key for secure communication.” Also relevant “including” to compiling34. The method step of “building an executable tamper resistant key module identi

executable tamper resistant key module including a private key of the asymmetits agents. To the extent any portion of the method step is performed by Google and/or its together with Google in a joint enterprise in the building and distribution of its mmobile apps under the direction and control of PayPal, or acts as agent, or on be

mobile apps. Building of an “executable tamper resistant code module” (that is, the mobile aasymmetric key pairs: (1) An asymmetric key pair must be included in order to send the mobile ap

(2) An asymmetric key pair must be included by PayPal in order to digitally 

mobile app has not been changed with the public key for Android compatible mThe asymmetric key pair that is included to digitally sign the mobile app is differ

securely upload the mobile app to the Google servers for distribution on the GoThus, at least one asymmetric key pair is included having the claimed public key 

the mobile app code can be sent uploaded to the Google servers using SSL/TLS ppair used to digitally sign the app) is complementary as described below by perfdata and/or creating and verifying signatures. As described in greater detail belsecurely upload the mobile app onto the Google servers by SSL/TLS when buildi

claimed asymmetric key pair(s) and the encrypted data. PayPal uploads their mobile apps to Google using a TLS connection – which begi

34 Although the exact language construed from the previous claims is not at issue in claim 34, also relevant is the Court’s construction 

and 10 to mean “one or more asymmetric key pairs, one of the asymmetric key pairs having the claimed public key and claimed privaperforming complementary functions, such as encrypting and decrypting data or creating and verifying signatures.” While not necesskey and private key in claim 34 must perform complementary functions. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
that allows PayPal and Google to exchange cryptographic parameters, including 

communication including upload of PayPal’s mobile apps to Google servers. A TLS handshake begins with PayPal sending a list of cipher suites supported by the following key exchange algorithms: 

Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

For each of the key exchange algorithms, PayPal and/or Google build an executa

key and the encrypted data. For RSA and RSA _PSK, the executable tamper resistant key module includes en

impossible for PayPal to send its mobile app to Google using SSL/TLS without en

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
tamper resistant key module also includes: 

1. Google’s RSA private key corresponding to Google’s RSA public key used 2. PayPal’s private key used to code-sign the mobile app. 

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, the executable tamper res

with Google subsequent to the TLS handshake, including at least the executable name, category, screenshots and description related to PayPal’s mobile apps). T

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s RSA private key used to sign the message containing Google’s 4. PayPal’s private key used to code-sign the mobile app. 

For DHE_DSS and DH_DSS, the executable tamper resistant key module include

the TLS handshake, including at least the executable compiled code related to it

and description related to PayPal’s mobile apps). The executable tamper resista

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s DSA private key used to sign the message containing Google’s 

4. PayPal’s private key used to code-sign the mobile app. 

For ECDH_ECDSA and ECDHE_ECDSA, the executable tamper resistant key mod

subsequent to the TLS handshake, including at least the executable compiled cocategory, screenshots and description related to PayPal’s mobile apps). The exe

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s ECDSA private key used to sign the message containing Google

4. PayPal’s private key used to code-sign the mobile app. 

PayPal builds an executable tamper resistant key module identified for a selectemobile app, which is an executable tamper resistant key module, as explained in 

program resident on a remote system, namely the Android operating system on 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
The mobile app comprises an executable tamper resistant key module that is id

described above and the encrypted data encrypted with the claimed public key made available for download from Google servers onto devices compatible with 

asymmetric key pair is used not only to upload the binary code files for the mobmetadata for the app, such as title, screenshots, and other resources or informa

during the upload process so that the mobile app can be identified by potential 

PayPal’s mobile app is each an executable tamper resistant key module because 

operating system as well as other applications or programs installed on a user’s 

and modification, as explained below; and because in building PayPal mobile apgenerated private key and the encrypted data including by way of example, the 

when the mobile app is securely uploaded onto the Google servers as described The tamper resistant key module includes several keys “used for secure commu

following: For RSA and RSA _PSK: 

1. Google’s RSA private key corresponding to Google’s RSA public key used 

2. PayPal’s private key used to code-sign the mobile app. 3. Symmetric key used for uploading the mobile app to Google subsequen4. Asymmetric keys and symmetric keys used for TLS communications duri

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA: 

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s RSA private key used to sign the message containing Google’s 4. PayPal’s private key used to code-sign the mobile app. 5. Shared master secret key used for uploading the mobile app to Google s

6. Asymmetric keys and symmetric keys used for TLS communications duri

For DHE_DSS and DH_DSS: 

35 See, e.g., https://developer.android.com/studio/publish/index.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s DSA private key used to sign the message containing Google’s 

4. PayPal’s private key used to code-sign the mobile app. 5. Shared master secret key used for uploading the mobile app to Google s6. Asymmetric keys and symmetric keys used for TLS communications duri

For ECDH_ECDSA and ECDHE_ECDSA: 

1. Google’s Diffie-Hellman private key corresponding to Google’s Diffie-He

secret. 

2. PayPal’s Diffie-Hellman private key used to compute the shared master 3. Google’s ECDSA private key used to sign the message containing Google

4. PayPal’s private key used to code-sign the mobile app. 5. Shared master secret key used for uploading the mobile app to Google s6. Asymmetric keys and symmetric keys used for TLS communications duri

PayPal’s mobile apps are tamper resistant, resistant to observation and modifica

1. Resistant to Observation Because App Source Code Is Compiled Before 

PayPal mobile apps are resistant to observation, at least in part, since PayPal co

Google – and uploads the binary output of the compilation process rather than 

See, Android Studio Users Guide, “Prepare for Release” stating “To release your 

users can install and run on their Android-powered devices. The release-ready p

compiled source code, resources, manifest file, and so on — and it is built using release-ready APK file is signed with your own certificate and it is optimized wit

https://developer.android.com/studio/publish/preparing.html, Last accessed on 

36 See, e.g., https://developer.android.com/studio/build/index.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
2. Resistant to Observation Because Upload To Google Is Over SSL/TLS 

PayPal’s mobile apps are made further resistant to observation, at least in part, of the building process. Android Developer Console (https://play.google.com/ap

communications when uploading PayPal’s apps, as evidenced by the “https” in tthe code from being observed in transit from the code developer to Google. The secure upload process starts with a TLS handshake procedure which uses as

asymmetric key pair. Specifically, PayPal negotiates with Google the cipher suite 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

For each of the above key exchange algorithms, Google and/or PayPal encrypts master secret, rendering the communication resistant to observation during traFor RSA and RSA _PSK, PayPal encrypts a random premaster secret with Google

Google. Google decrypts the premaster secret with its matched RSA private key

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
master secret which is then used by both PayPal and Google to encrypt all subse

For the other key exchange algorithms, namely Diffie-Hellman based algorithms 

ECDH_RSA, ECDH_ECDSA and ECDHE_ECDSA, PayPal sends its Diffie-Hellman pu

to PayPal. PayPal then uses Google’s Diffie-Hellman public key combined with Psecret. Google in turn uses PayPal’s Diffie-Hellman public key combined with Go

premaster secret. PayPal and Google both use the premaster secret to compute encrypt all subsequent communications between PayPal and Google. 

3. Resistant to Modification Because App Binary Is Code Signed 

The mobile app code is made resistant to modification, at least in part, because must sign the mobile app submission with his/her asymmetric developer key th

impersonator38. 

Android requires that the user generates an asymmetric key all apps be d

uses this certificate to identify the author of an app Source: https://developer.android.com/studio/publish/app-signing.html

A public-key certificate, also known as a digital certificate or an identity c

as some other metadata identifying the owner of the key (for example, ncorresponding private key. When you sign an APK, the signing tool attaches the public-key certificate that uniquely associates the APK to you and your corresponding private kauthentic and come from the original author. 

A keystore is a binary file that contains one or more private keys. When y

generate a new keystore and private key or use a keystore and private keSource: https://developer.android.com/studio/publish/app-signing.html

37 For Diffie-Hellman (DH) based algorithms such as DH_RSA, DHE_RSA, ECDH_RSA, ECDHE_RSA, DH_DSS, DHE_DSS, ECDH_ECDSA and 

Diffie-Hellman public key and encrypts the hash with their RSA/DSA/ECDSA private key (i.e. signing the message). Google then sends t

can authenticate the Google server by decrypting the hash using Google’s public key and matching the decryption result to a hash of tPayPal knows that the message originated from Google and not from a malicious third party. 38 See, e.g., https://developer.android.com/tools/publishing/app-signing.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171107004101/https://develope

accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: http://web.archive.org/web/20171107004101/https://develope

accessed on Mar 19, 2020Source: http://web.archive.org/web/20171107004101/https://developeaccessed on Mar 19, 2020

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
PayPal complies with Google’s instructions on code signing as shown by PayPal’

files CERT.SF and CERT.RSA in PayPal’s Android apps which are generated during 

Source: Contents of Venmo (https://play.google.com/store/apps/details?id=com

Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: Contents of Venmo (https://play.google.com/store/apps/details?id=com

Mar 19, 2020 Asymmetrical key cryptography and hashing algorithms are used to create the uis used to sign the resources in an application package, including the compiled cthe digital code signing is used to code sign the app. This private key is included key of the claimed generated asymmetric key pair because it does not match thconstruction. Hashes are created for every resource in the application package with the help oprevent unauthorized changes. The hashes are encrypted with a private key. Aft

created. By signing the app binary with a digital signature, PayPal’s mobile apps are tamp

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
verify that the application is being distributed by trusted source (i.e. PayPal) and 

can be verified by the corresponding public key generated as part of the pair. Th

Accordingly PayPal’s Android mobile apps establish SSL/TLS communications witinvolving asymmetric key encryption. SSL/TLS ensures secure communication an

sending the executable tamper resistant key module to the remote system. 

Upon information and belief, the method step of sending the executable tampe

and/or its agents – whose acts are attributable to PayPal (i) because PayPal wor

distribution of its mobile apps, or (ii) because Google distributes and markets Paas agent, or on behalf of PayPal, in the building, marketing and distribution of Pa

Alternatively, to the extent any portion of this method step is performed by Payparticipation in and the receipt of a benefit, namely, the distribution of PayPal’s 

mandatory procedures and guidelines dictated by Google in the building and up

Google in the building, marketing and distribution of PayPal’s mobile apps. 

PayPal’s mobile apps are sent or downloaded from Google servers and are exec

When a user accesses Google Play Store – and requests to download PayPal app

Google servers to the remote device(s). Further, the step of “sending” PayPal mobile apps to the remote system occurs 

apps, to the extent required by the claims, also includes a private key and data eIn particular, PayPal mobile apps sent to users’ remote devices are tamper resis

1. Resistant to Observation Because App is Downloaded in Compiled For

PayPal mobile apps are resistant to observation, at least in part, since PayPal coGoogle – and uploads the binary output of the compilation process rather than 

compiled source code from Google rather than the source code itself39.See, Android Studio Users Guide, “Prepare for Release” stating “To release your 

39 See, e.g., https://developer.android.com/studio/build/index.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
users can install and run on their Android-powered devices. The release-ready p

compiled source code, resources, manifest file, and so on — and it is built using release-ready APK file is signed with your own certificate and it is optimized wit

https://developer.android.com/studio/publish/preparing.html, Last accessed on 

2. Resistant to Observation Because Download from Google Is Over SSL/T

PayPal’s mobile apps are made further resistant to observation, at least in part, 

from Google servers. PayPal app users establish SSL/TLS communications with P

https://play.google.com/store/apps/details?id=com.venmo&hl=en_US for Venmas evidenced by the “https” in the URL. Sending the mobile app code by SSL/TLS 

Google to the user’s remote system. The secure download process starts with a TLS handshake procedure which uses 

one asymmetric key pair. Specifically, user’s remote device negotiates with Goo

for the handshake.: 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Each of these algorithms necessitates generating one or more asymmetric key pencrypting the mobile app download. For RSA and RSA _PSK, Google server generates an RSA public-private key pair. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, Google server generates a

key pair40. The user’s remote device also generates a second Diffie-Hellman pubFor DHE_DSS and DH_DSS, Google server generates a DSA public-private key pa

remote device also generates a second Diffie-Hellman public-private key pair. For ECDH_ECDSA and ECDHE_ECDSA, Google server generates an ECDSA public

The user’s remote device also generates a second Diffie-Hellman public-private 

40 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 50-51, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

The generated asymmetric key pairs are then used to compute a shared master 

that it is resistant to observation during transit.For RSA and RSA _PSK, the RSA public-private key pair is used to encrypt a rand

user’s remote device to compute a master secret. Google uses the master secre

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
decrypt the downloaded mobile app according to the TLS protocol. 

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, Google server generates a

key pair41. The user’s remote device also generates a second Diffie-Hellman puband the user’s Diffie-Hellman public key to compute a premaster secret, and sub

the user’s Diffie-Hellman private key and Google’s Diffie-Hellman public key to c

secret that Google uses to encrypt the mobile app and the user’s remote device protocol. For DHE_DSS and DH_DSS, Google server generates a DSA public-private key pa

remote device also generates a second Diffie-Hellman public-private key pair. G

Hellman public key to compute a premaster secret, and subsequently compute 

Hellman private key and Google’s Diffie-Hellman public key to compute the samuses to encrypt the mobile app and the user’s remote device uses to decrypt the For ECDH_ECDSA and ECDHE_ECDSA, Google server generates an ECDSA public

The user’s remote device also generates a second Diffie-Hellman public-private user’s Diffie-Hellman public key to compute a premaster secret, and subsequenDiffie-Hellman private key and Google’s Diffie-Hellman public key to compute th

Google uses to encrypt the mobile app and the user’s remote device uses to dec

3. Resistant to Modification Because Mobile App is Code Signed 

The downloaded mobile app code is resistant to modification, at least in part, beallows users’ remote systems to verify that the downloaded app binary is authe

41 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
dictates that each developer must sign the mobile app submission with his/her 

modified by a third party impersonator42. 

Android requires that the user generates an asymmetric key all apps be d

uses this certificate to identify the author of an app Source: https://developer.android.com/studio/publish/app-signing.html

A public-key certificate, also known as a digital certificate or an identity c

as some other metadata identifying the owner of the key (for example, ncorresponding private key. When you sign an APK, the signing tool attaches the public-key certificate that uniquely associates the APK to you and your corresponding private kauthentic and come from the original author. 

A keystore is a binary file that contains one or more private keys. When y

generate a new keystore and private key or use a keystore and private keSource: https://developer.android.com/studio/publish/app-signing.html

PayPal complies with Google’s instructions on code signing as shown by PayPal’files CERT.SF and CERT.RSA in PayPal’s Android mobile apps which are generate

42 See, e.g., https://developer.android.com/tools/publishing/app-signing.html, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: Contents of Venmo (https://play.google.com/store/apps/details?id=com

Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: Contents of Venmo (https://play.google.com/store/apps/details?id=com

Mar 19, 2020 By signing the app binary with a digital signature, PayPal’s mobile apps are tampverify that the application is being distributed by trusted source (i.e. PayPal) and can be verified by the corresponding public key generated as part of the pair. ThAccordingly PayPal’s Android mobile apps establish SSL/TLS communications witinvolving asymmetric key encryption. SSL/TLS ensures secure communication an

4. Resistant to Observation Because Mobile App is Stored on Remote Sys

The mobile app is made further resistant to observation because when downloa

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
encrypted form. Android implements disk encryption for encrypting the operati

which further renders PayPal app resistant to observation43. 

5. Resistant to Observation Because Mobile App Securely Communicates 

PayPal’s mobile apps are made further resistant to observation, at least in part, 

during operation. PayPal app users establish SSL/TLS communications with Paynecessary to keep source code as well as user identity and activity from being oversa. The secure communications process starts with a TLS handshake procedure whi

least one asymmetric key pair. Specifically, user’s remote device negotiates with 

will be used for the handshake. 

43 See, e.g., https://source.android.com/security/encryption/, Last accessed on Mar 19, 2020 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Each of these algorithms necessitates generating one or more asymmetric key pencrypting communication between PayPal and user’s remote device. For RSA and RSA _PSK, PayPal server generates an RSA public-private key pair. 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, PayPal server generates an 

key pair44. The user’s remote device also generates a second Diffie-Hellman pubFor DHE_DSS and DH_DSS, PayPal server generates a DSA public-private key pa

remote device also generates a second Diffie-Hellman public-private key pair. For ECDH_ECDSA and ECDHE_ECDSA, PayPal server generates an ECDSA public-The user’s remote device also generates a second Diffie-Hellman public-private 

44 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 48-49, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: https://tools.ietf.org/html/rfc5246 at 50-51, Last accessed on Mar 19, 2

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
Source: The Transport Layer Security (TLS) Protocol Version 1.2, IETF RFC 5246, 

The generated asymmetric key pairs are then used to compute a shared master 

between PayPal and the user’s remote device so that they are resistant to obserFor RSA and RSA _PSK, the RSA public-private key pair is used to encrypt a rand

user’s remote device to compute a master secret. PayPal and the user’s remote 

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20 
communication messages. 

For DHE_RSA, ECDHE_RSA, DH_RSA and ECDH_RSA, PayPal server generates an 

key pair45. The user’s remote device also generates a second Diffie-Hellman puband the user’s Diffie-Hellman public key to compute a premaster secret, and subthe user’s Diffie-Hellman private key and Google’s Diffie-Hellman public key to c

secret for encrypting and decrypting communication messages. 

For DHE_DSS and DH_DSS, PayPal server generates a DSA public-private key paremote device also generates a second Diffie-Hellman public-private key pair. P

Hellman public key to compute a premaster secret, and subsequently compute 

Hellman private key and Google’s Diffie-Hellman public key to compute the sam

encrypting and decrypting communication messages. For ECDH_ECDSA and ECDHE_ECDSA, PayPal server generates an ECDSA public-The user’s remote device also generates a second Diffie-Hellman public-private 

user’s Diffie-Hellman public key to compute a premaster secret, and subsequenDiffie-Hellman private key and Google’s Diffie-Hellman public key to compute th

encrypting and decrypting communication messages. 

45 ECDH and ECDHE algorithms require generating at the server and the client, elliptical curve parameters that constitute a Diffie-Hellhttps://tools.ietf.org/html/rfc5246 page 49-52, https://tools.ietf.org/html/rfc7525 page 12, http://www.cse.hut.fi/fi/opinnot/T-110.5http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140sp/140sp2897.pdf, http://www.networkworld.com/article/2268575/lahttp://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf, Implementing SSL / TLS Using Cryptography and PKI by Joshua DavieNetworks and Cybersecurity By Chwan-Hwa (John) Wu, J. David Irwin, ISBN 1466572140, 9781466572140, Page 1021, which state that ECDH requires generating a Diffie-Hellman public-private key pair, Last ac

Case 1:20-cv-00404-RP Document 1-2 Filed 04/16/20