NIST Special Publication 800-78-2 Cryptographic Algorithms and 

Key Sizes for Personal Identity 

Verification

February 2010

U.S. Department of Commerce

Gary Locke, Secretary

.

I N F O R M A T I O N S E C U R I T Y

National Institute of Standards and Technology

W. Timothy Polk

Donna F. Dodson

William. E. Burr

Computer Security Division

Information Technology Laboratory

National Institute of Standards and Technology

Gaithersburg, MD, 20899-8930

Dr. Patrick D. Gallagher, Director

.
Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

Reports on Computer Systems Technology 

The Information Technology Laboratory (ITL) at the National Institute of Standards and 

Technology (NIST) promotes the U.S. economy and public welfare by providing technical 

leadership for the Nation’s measurement and standards infrastructure. ITL develops tests, test 

methods, reference data, proof of concept implementations, and technical analyses to advance 

the development and productive use of information technology. ITL’s responsibilities include 

the development of management, administrative, technical, and physical standards and 

guidelines for the cost-effective security and privacy of non-national security-related information 

in Federal information systems. This special publication 800-series reports on ITL’s research, 

guidelines, and outreach efforts in information system security, and its collaborative activities 

with industry, government, and academic organizations. 

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Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

Table of Contents 

1. INTRODUCTION ...............................................................................................................................................1

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1.2 PURPOSE ..........................................................................................................................................................

1.1 AUTHORITY .....................................................................................................................................................

1.3 SCOPE ..............................................................................................................................................................

1.4 AUDIENCE AND ASSUMPTIONS.........................................................................................................................2

1.5 DOCUMENT OVERVIEW....................................................................................................................................2

2. APPLICATION OF CRYPTOGRAPHY IN FIPS 201 ....................................................................................

3. ON CARD CRYPTOGRAPHIC REQUIREMENTS.......................................................................................

3.2 A THENTICATION INFORMATION STORED ON THE PIV CARD .........................................................................

3.1 PIV CRYPTOGRAPHIC KEYS.............................................................................................................................

3.2.1 Specification of Digital Signatures on Authentication Information ........................................................

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3.2.3 Specification of Message Digests in the SP 800-73 Security Object .......................................................

3.2.2 Specification of Public Keys In X.509 Certificates..................................................................................

4. CERTIFICATE STATUS INFORMATION.....................................................................................................

5. PIV CARD MANAGEMENT KEYS .................................................................................................................

6. IDENTIFIERS FOR PIV CARD INTERFACES ...........................................................................................

6.2 PIV CARD ALGORITHM IDENTIFIERS .............................................................................................................

6.1 KEY REFERENCE VALUES ..............................................................................................................................

6.3 ALGORITHM IDENTIFIERS FOR PIV KEY TYPES..............................................................................................

APPENDIX A— ACRONYMS ................................................................................................................................

APPENDIX B— REFERENCES ............................................................................................................................

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List of Tables 

Table 3-1. Algorithm and Key Size Requirements for PIV Key Types ........................................

Table 3-3. Signature Algorithm and Key Size Requirements for PIV Information ......................

Table 3-2. RSA Public Key Exponents..........................................................................................

Table 3-4. FIPS 201 Signature Algorithm Object Identifiers........................................................

Table 3-5. Public Key Object Identifiers for PIV Key Types........................................................

Table 3-6. ECC Parameter Object Identifiers for Approved Curves.............................................

Table 3-7. Hash Algorithm Object Identifiers ...............................................................................

Table 5-1. Algorithm and Key Size Requirements for Card Management Keys ..........................

Table 6-1. Key References for PIV Key Types ...........................................................................

Table 6-2. Identifiers for Supported Cryptographic Algorithms .................................................

Table 6-3. PIV Card Keys: Key References and Algorithms ......................................................
Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

1. Introduction 

Homeland Security Presidential Directive (HSPD) 12 mandated the creation of new standards for 

interoperable identity credentials for physical and logical access to Federal government locations 

and systems. Federal Information Processing Standard 201 (FIPS 201), Personal Identity 

Verification (PIV) of Federal Employees and Contractors, was developed to establish standards 

for identity credentials [FIPS201]. This document, Special Publication 800-78-2, specifies the 

cryptographic algorithms and key sizes for PIV systems and is a companion document to FIPS 

201. 

1.1 Authority 

This document has been developed by the National Institute of Standards and Technology 

(NIST) in furtherance of its statutory responsibilities under the Federal Information Security 

Management Act (FISMA) of 2002, Public Law 107-347. 

NIST is responsible for developing standards and guidelines, including minimum requirements, 

for providing adequate information security for all agency operations and assets, but such 

standards and guidelines shall not apply to national security systems. This recommendation is 

consistent with the requirements of the Office of Management and Budget (OMB) Circular A130, Section 8b(3), Securing Agency Information Systems, as analyzed in A-130, Appendix IV: 

Analysis of Key Sections. Supplemental information is provided in A-130, Appendix III. 

This recommendation has been prepared for use by Federal agencies. It may be used by nongovernmental organizations on a voluntary basis and is not subject to copyright. Nothing in this 

document should be taken to contradict standards and guidelines made mandatory and binding 

on Federal agencies by the Secretary of Commerce under statutory authority. Nor should this 

recommendation be interpreted as altering or superseding the existing authorities of the Secretary 

of Commerce, Director of OMB, or any other Federal official. 

1.2 Purpose 

FIPS 201 defines requirements for the PIV lifecycle activities including identity proofing, 

registration, PIV Card issuance, and PIV Card usage. FIPS 201 also defines the structure of an 

identity credential that includes cryptographic keys. This document contains the technical 

specifications needed for the mandatory and optional cryptographic keys specified in FIPS 201 

as well as the supporting infrastructure specified in FIPS 201 and the related Special Publication 

800-73, Interfaces for Personal Identity Verification [SP800-73], and SP 800-76, Biometric Data 

Specification for Personal Identity Verification [SP800-76], that rely on cryptographic functions. 

1.3 Scope 

The scope of this recommendation encompasses the PIV Card, infrastructure components that 

support issuance and management of the PIV Card, and applications that rely on the credentials 

supported by the PIV Card to provide security services. The recommendation identifies 

acceptable symmetric and asymmetric encryption algorithms, digital signature algorithms, key 

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Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

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establishment schemes, and message digest algorithms, and specifies mechanisms to identify the 

algorithms associated with PIV keys or digital signatures. 

Algorithms and key sizes have been selected for consistency with applicable Federal standards 

and to ensure adequate cryptographic strength for PIV applications. All cryptographic 

algorithms employed in this specification provide at least 80 bits of security strength. For 

detailed guidance on the strength of cryptographic algorithms, see [SP800-57(1)], 

Recommendation on Key Management – Part 1: General. 

1.4 Audience and Assumptions 

This document is targeted at Federal agencies and implementers of PIV systems. Readers are 

assumed to have a working knowledge of cryptography and Public Key Infrastructure (PKI) 

technology. 

1.5 Document Overview 

The document is organized as follows: 

 Section 1, Introduction, provides the purpose, scope, audience, and assumptions of the 

document and outlines its structure. 

 Section 2, Application of Cryptography in FIPS 201, identifies the cryptographic 

mechanisms and objects that employ cryptography as specified in FIPS 201 and its 

supporting documents. 

 Section 3, On Card Cryptographic Requirements, describes the cryptographic 

requirements for cryptographic keys and authentication information stored on the PIV 

Card. 

 Section 4, Certificate Status Information, describes the cryptographic requirements for 

status information generated by PKI Certification Authorities (CA) and Online Certificate 

Status Protocol (OCSP) responders. 

 Section 5, PIV Card Management Keys, describes the cryptographic requirements for 

management of information stored on the PIV Card. 

 Section 6, Identifiers for PIV Card Interfaces, specifies key reference values and 

algorithm identifiers for the application programming interface and card commands 

defined in [SP 800-73]. 

 Appendix A, Acronyms, contains the list of acronyms used in this document. 

 Appendix B, References, contains the list of documents used as references by this 

document. 
Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

2. Application of Cryptography in FIPS 201 

FIPS 201 employs cryptographic mechanisms to authenticate cardholders, secure information 

stored on the PIV Card, and secure the supporting infrastructure. 

FIPS 201 and its supporting documents specify a suite of keys to be stored on the PIV Card for 

personal identity verification, digital signature generation, and key management. The PIV 

cryptographic keys specified in FIPS 201 are: 

 the asymmetric PIV Authentication Key; 

 a Card Authentication Key, which may be symmetric or asymmetric; 

 an asymmetric Digital Signature Key for signing documents and messages; and 

 an asymmetric Key Management Key, supporting key establishment or key transport. 

The cryptographic algorithms, key sizes, and parameters that may be used for these keys are 

specified in Section 3.1. PIV Cards must implement private key computations for one or more of 

the algorithms identified in this section. 

Cryptographically protected objects specified in FIPS 201, SP 800-73, and SP 800-76 include: 

 the X.509 certificates for each asymmetric key on the PIV Card; 

 a digitally signed Card Holder Unique Identifier (CHUID); 

 digitally signed biometrics using the Common Biometric Exchange Formats Framework 

(CBEFF) signature block; and 

 the SP 800-73 Security Object, which is a digitally signed hash table. 

The cryptographic algorithms, key sizes, and parameters that may be used to protect these 

objects are specified in Section 3.2. Certification Authorities (CA) and card management 

systems that protect these objects must support one or more of the cryptographic algorithms, key 

sizes, and parameters specified in Section 3.2. 

Applications may be designed to use any or all of the cryptographic keys and objects stored on 

the PIV Card. Where maximum interoperability is required, applications should support all of 

the identified algorithms, key sizes, and parameters specified in Sections 3.1 and 3.2. 

FIPS 201 requires CAs and Online Certificate Status Protocol (OCSP) responders to generate 

and distribute digitally signed Certificate Revocation Lists (CRL) and OCSP status messages. 

These revocation mechanisms support validation of the PIV Card, the PIV cardholder, the 

cardholder’s digital signature key, and the cardholder’s key management key. 

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The signed revocation mechanisms specified in FIPS 201 are: 

 X.509 CRLs that specify the status of a group of X.509 certificates; and 

 OCSP status response messages that specify the status of a particular X.509 certificate. 

The cryptographic algorithms, key sizes, and parameters that may be used to sign these 

mechanisms are specified in Section 4. Section 4 also describes rules for encoding the signatures 

to ensure interoperability. 

FIPS 201 permits optional card management operations. These operations may only be 

performed after the PIV Card authenticates the card management system. Card management 

systems are authenticated through the use of card management keys. The cryptographic 

algorithms and key sizes that may be used for these keys are specified in Section 5. 
Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

3. On Card Cryptographic Requirements 

FIPS 201 identifies a suite of objects that are stored on the PIV Card for use in authentication 

mechanisms or in other security protocols. These objects may be divided into three classes: 

cryptographic keys, signed authentication information stored on the PIV Card, and message 

digests of information stored on the PIV Card. Cryptographic requirements for PIV keys are 

detailed in Section 3.1. Cryptographic requirements for other stored objects are detailed in 

Section 3.2. 

3.1 PIV Cryptographic Keys 

FIPS 201 specifies four different classes of cryptographic keys to be used as credentials by the 

PIV cardholder: 

 the mandatory PIV Authentication Key; 

 an optional Card Authentication Key; 

 an optional Digital Signature Key; and 

 an optional Key Management Key. 

Table 3-1 establishes specific requirements for cryptographic algorithms and key sizes for each 

key type. Table 3-1 also specifies time periods with different sets of acceptable algorithms for 

each key type. Note that use of 1024-bit RSA for digital signature and key management keys 

was phased out in 2008. The use of 1024-bit RSA for authentication keys is permitted to 

leverage current products and promote efficient adoption of FIPS 201, but must be phased out by 

12/31/2013. Two key Triple-DES (2TDEA) authentication keys must be phased out by 

12/31/2010. These requirements anticipate that digital signature and key management keys will 

be used to protect data for longer periods of time, while data enciphered solely for authentication 

is usually a random challenge (rather than sensitive information) and is generally not retained. 

In addition to the key sizes, keys must be generated using secure parameters. Rivest, Shamir, 

Adleman (RSA) keys must be generated using appropriate exponents, as specified in Table 3-2. 

Elliptic curve keys must correspond to one of the following recommended curves from 

[FIPS186]: 

 Curve P-256; or

 Curve P-384. 

To promote interoperability, this specification further limits PIV Authentication and Card 

Authentication elliptic curve keys to a single curve (P-256). PIV cryptographic keys for digital 

signatures and key management may use P-256 or P-384, based on application requirements. 

There is no phase out date specified for either curve. 

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Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

Table 3-1. Algorithm and Key Size Requirements for PIV Key Types 

PIV Key Type Time Period for Use Algorithms and Key Sizes 

Through 12/31/2013 RSA (1024 or 2048 bits) 

ECDSA (Curve P-256) 

PIV Authentication Key 

After 12/31/2013 RSA (2048 bits) 

ECDSA (Curve P-256) 

Through 12/31/2010 2TDEA 

3TDEA 

AES-128, AES-192, or AES-256 

RSA (1024 or 2048 bits) 

ECDSA (Curve P-256) 

1/1/2011 through 

12/31/2013 

3TDEA 

AES-128, AES-192, or AES-256 

RSA (1024 or 2048 bits) 

ECDSA (Curve P-256) 

Card Authentication Key 

After 12/31/2013 3TDEA 

AES-128, AES-192, or AES-256 

RSA (2048 bits) 

ECDSA (Curve P-256) 

Digital Signature Key After 12/31/2008 RSA (2048 bits) 

ECDSA (Curves P-256 or P-384) 

Key Management Key After 12/31/2008 RSA key transport (2048 bits); 

ECDH (Curves P-256 or P-384) 

This specification also restricts the size of the RSA exponent that may be associated with PIV 

keys. Implementations of this specification must choose an exponent greater than or equal to 

65,537. Upper bounds for the exponent are based on key length; see Table 3-2 for complete 

details. 

Table 3-2. RSA Public Key Exponents 

RSA Modulus Size Minimum exponent Maximum exponent 

1024 65,537 (216 + 1) 2864 – 1 

2048 65,537 21824 – 1 

This specification requires that the Key Management Key must be an RSA key transport key or 

an Elliptic Curve Diffie-Hellman (ECDH) key. The specifications for RSA key transport are 

[PKCS1] and [SP800-56B]; the specification for ECDH is [SP800-56A]. 

3.2 Authentication Information Stored on the PIV Card 

3.2.1 Specification of Digital Signatures on Authentication Information 

FIPS 201 requires the use of digital signatures to protect the integrity and authenticity of 

information stored on the PIV Card. FIPS 201 and SP 800-73 require digital signatures on the 

following objects stored on the PIV Card: 

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Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

 X.509 public key certificates; 

 the CHUID; 

 biometric information (e.g., fingerprints); and 

 the SP 800-73 Security Object. 

Approved Digital Signature algorithms are specified in [FIPS 186]. Table 3-3 provides specific 

requirements for digitally signed information stored on the PIV Card. The first column specifies 

two time periods; the remaining columns specify public key algorithms and hash algorithms for 

generating digital signatures. For signatures on the X.509 public key certificates, the CHUID, 

Security Object, and stored biometrics, the hash algorithm that must be used to generate the 

signature is determined by the signature generation date. Agencies are cautioned that generating 

digital signatures with elliptic curve algorithms may initially limit interoperability. 

Table 3-3. Signature Algorithm and Key Size Requirements for PIV Information 

Signature 

Generation Date1 Public Key Algorithms and Key Sizes 

Hash Algorithms Padding Scheme 

SHA-1 PKCS #1 v1.5 

RSA (2048 or 3072) SHA-256 PKCS #1 v1.5 

SHA-256 PSS 

ECDSA (Curve P-256) SHA-256 N/A 

Through 

12/31/2010 

ECDSA (Curve P-384) SHA-384 N/A 

RSA (2048 or 3072) SHA-256 PKCS #1 v1.5 

SHA-256 PSS 

ECDSA (Curve P-256) SHA-256 N/A 

After 12/31/2010 

ECDSA (Curve P-384) SHA-384 N/A 

Note: 2010 is a transition period where both SHA-1 and SHA-256 are recommended for 

generation of RSA signatures. Beginning in 2011, only SHA-256 may be used to generate RSA 

signatures on PIV objects. RSA signatures generated with SHA-256 may use either the PKCS 

#1 v1.5 padding scheme or the Probabilistic Signature Scheme (PSS) padding as defined in 

[PKCS1]. (This specification does not permit generation of RSA signatures with SHA-1 and 

PSS padding, since most current implementations of RSA use the padding scheme defined in 

PKCS #1 v1.5). The PSS padding scheme OID is independent of the hash algorithm; the hash 

algorithm is specified as a parameter (for details, see [PKCS1]). Implementations of this 

specification must use the SHA-256 hash algorithm when generating RSA-PSS signatures. 

Agencies may wish to transition to the PSS padding scheme as they transition to SHA-256. 

 

To determine signature generation dates for the purpose of PIV Data Model Testing as outlined in SP 800-85B, the 

following date attributes should be used: 

• For each X.509 public key certificate: the notBefore time in the certificate. 

• For all other objects: 

o the signingTime attribute (if present) in the object’s Cryptographic Message Syntax (CMS), or 

o the notBefore time encoded in the PIV Authentication certificate if the signingTime attribute is 

omitted in the object’s CMS. 

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Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

FIPS 201, SP 800-73, and SP 800-76 specify formats for the CHUID, the Security Object, the 

biometric information, and X.509 public key certificates, which rely on object identifiers (OID) 

to specify which signature algorithm was used to generate the digital signature. The object 

identifiers specified in Table 3-4, below, must be used in FIPS 201 implementations to identify 

the signature algorithm. 

Table 3-4. FIPS 201 Signature Algorithm Object Identifiers 

Signature Algorithm Object Identifier 

RSA with SHA-1 and 

PKCS v1.5 padding 

sha1WithRSAEncryption ::= {iso(1) member-body(2) us(840) rsadsi(113549) 

pkcs(1) pkcs-1(1) 5} 

RSA with SHA-256 and 

PKCS v1.5 padding 

sha256WithRSAEncryption ::= {iso(1) member-body(2) us(840) rsadsi(113549) 

pkcs(1) pkcs-1(1) 11} 

RSA with SHA-256 and 

PSS padding 

id-RSASSA-PSS ::= {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) 

pkcs-1(1) 10} 

ECDSA with SHA-256 ecdsa-with-SHA256 ::= {iso(1) member-body(2) us(840) ansi-X9-62(10045) 

signatures(4) ecdsa-with-SHA2 (3) 2} 

ECDSA with SHA-384 ecdsa-with-SHA384 ::= {iso(1) member-body(2) us(840) ansi-X9-62(10045) 

signatures(4) ecdsa-with-SHA2 (3) 3} 

3.2.2 Specification of Public Keys In X.509 Certificates 

FIPS 201 requires generation and storage of an X.509 certificate to correspond with each 

asymmetric private key contained on the PIV Card. X.509 certificates include object identifiers 

to specify the cryptographic algorithm associated with a public key. Table 3-5, below, specifies 

the object identifiers that may be used in certificates to indicate the algorithm for a subject public 

key. 

Table 3-5. Public Key Object Identifiers for PIV Key Types 

PIV Key Type Asymmetric 

Algorithm Object Identifier 

PIV Authentication Key; RSA {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 1} 

Card Authentication Key; 

Digital Signature Key ECDSA {iso(1) member-body(2) us(840) ansi-X9-62(10045) 

id-publicKeyType(2) 1} 

RSA {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 1} 

Key Management Key ECDH {iso(1) member-body(2) us(840) ansi-X9-62(10045) 

id-publicKeyType(2) 1} 

A single object identifier is specified in Table 3-5 for all elliptic curve keys. An additional 

object identifier must be supplied in a parameters field to indicate the elliptic curve associated 

with the key. Table 3-6, below, identifies the named curves and associated OIDs. (RSA 

exponents are encoded with the modulus in the certificate’s subject public key, so the OID is not 

affected.) 

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Table 3-6. ECC Parameter Object Identifiers for Approved Curves 

Asymmetric 

Algorithm Object Identifier 

Curve P-256 ansip256r1 ::= { iso(1) member-body(2) us(840) ansi-X9-62(10045) curves(3) prime(1) 7 } 

Curve P-384 ansip384r1 ::= { iso(1) identified-organization(3) certicom(132) curve(0) 34 } 

3.2.3 Specification of Message Digests in the SP 800-73 Security Object 

SP 800-73 mandates inclusion of a Security Object consistent with the Authenticity/Integrity 

Code defined by the International Civil Aviation Organization (ICAO) in [MRTD]. This object 

contains message digests of other digital information stored on the PIV Card and is digitally 

signed. This specification requires that the message digests of digital information be computed 

using the same hash algorithm used to generate the digital signature on the Security Object. The 

set of acceptable algorithms depends upon the signature generation date, as specified in Table 

3-3. The Security Object format identifies the hash algorithm used when computing the message 

digests by inclusion of an object identifier; the appropriate object identifiers are identified in 

Table 3-7. 

Table 3-7. Hash Algorithm Object Identifiers 

Hash Algorithm Algorithm OID 

SHA-1 id-sha1 ::= {iso(1) identified-organization(3) oiw(14) secsig(3) algorithms(2) 26} 

SHA-256 id-sha256 ::= {joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3) 

nistalgorithm(4) hashalgs(2) 1} 

SHA-384 id-sha384 ::= {joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3) 

nistalgorithm(4) hashalgs(2) 2} 
Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

4. Certificate Status Information 

The FIPS 201 functional component PIV Card Issuance and Management Subsystem generates 

and distributes status information for PIV asymmetric keys. FIPS 201 mandates two formats for 

certificate status information: 

 X.509 CRLs; and

 OCSP status response messages. 

The CRLs and OCSP status responses are digitally signed to support authentication and integrity 

using a key size and hash algorithm that satisfy the requirements for signing PIV information, as 

specified in Table 3-32, and that are at least as large as the key size and hash algorithm used to 

sign the certificate. 

 

CRLs and OCSP messages rely on object identifiers to specify which signature algorithm was 

used to generate the digital signature. The object identifiers specified in Table 3-4 must be used 

in CRLs and OCSP messages to identify the signature algorithm. 

 

2

 CRLs and OCSP status responses that only provide status information for certificates that were signed with 1024-

bit RSA keys may be signed using 1024-bit RSA keys. 

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5. PIV Card Management Keys 

PIV Cards may support card activation by the card management system to support card 

personalization and post-issuance card update. PIV Cards that support card personalization and 

post-issuance updates perform a challenge response protocol using a symmetric cryptographic 

key (i.e., the PIV Card Management Key) to authenticate the card management system. After 

successful authentication, the card management system can modify information stored in the PIV 

Card. Table 5-1, below, establishes specific requirements for cryptographic algorithms and key 

sizes for PIV Card Management Keys according to the card expiration date. 

Table 5-1. Algorithm and Key Size Requirements for Card Management Keys 

Card Expiration Date Algorithm 

Through 12/31/2010 2TDEA 

3TDEA 

AES-128, AES-192, or AES-256 

After 12/31/2010 3TDEA 

AES-128, AES-192, or AES-256 

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6. Identifiers for PIV Card Interfaces 

SP 800-73 defines an application programming interface, the End-Point PIV Client Application 

Programming Interface (Part 3), and a set of mandatory card commands, the End-Point PIV 

Card Application Card Command Interface (Part 2). The command syntaxes for these interfaces 

identify PIV keys using one-byte key references; their associated algorithms are specified using 

one-byte algorithm identifiers. The same identifiers are used in both interfaces. 

Section 6.1 specifies the key reference values for each of the PIV key types. Section 6.2 defines 

algorithm identifiers for each cryptographic algorithm supported by this specification. Section 

6.3 identifies valid combinations of key reference values and algorithm identifiers based on the 

period of use. 

6.1 Key Reference Values 

A PIV Card key reference is a one-byte identifier that specifies a cryptographic key according to 

its PIV Key Type. Table 6-1 defines the key reference values used on the PIV interfaces for PIV 

Key Types. 

Table 6-1. Key References for PIV Key Types 

PIV Key Type Key Reference Value 

PIV Authentication Key '9A' 

Card Management Key '9B' 

Digital Signature Key '9C' 

Key Management Key '9D' 

Card Authentication Key '9E' 

6.2 PIV Card Algorithm Identifiers 

A PIV Card algorithm identifier is a one-byte identifier that specifies a cryptographic algorithm 

and key size. For symmetric cryptographic operations, the algorithm identifier also specifies a 

mode of operation (i.e., ECB). Table 6-2 lists the algorithm identifiers for the cryptographic 

algorithms that may be recognized on the PIV interfaces. All other algorithm identifier values 

are reserved for future use. 

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Table 6-2. Identifiers for Supported Cryptographic Algorithms 

Algorithm Identifier Algorithm – Mode 

'00' 3 Key Triple DES – ECB 

'01' 2 Key Triple DES – ECB 

'03' 3 Key Triple DES – ECB 

'06' RSA 1024 bit modulus, 65,537 ≤ exponent ≤ 2864 - 1 

'07' RSA 2048 bit modulus, 65,537 ≤ exponent ≤ 21824 - 1 

'08' AES-128 – ECB 

'0A' AES-192 – ECB 

'0C' AES-256 – ECB 

'11' ECC: Curve P-256 

'14' ECC: Curve P-384 

Note that both the '00' and '03' algorithm identifiers correspond to 3 Key Triple DES – ECB. 

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6.3 Algorithm Identifiers for PIV Key Types 

Table 6-3 summarizes the set of algorithms supported for each key reference value based on the 

time period of use. 

Table 6-3. PIV Card Keys: Key References and Algorithms 

PIV Key Type Key Reference 

Value Time Period for Use Permitted Algorithm Identifiers 

Through 12/31/2013 '06', '07', '11' PIV Authentication Key '9A' 

After 12/31/2013 '07', '11' 

Through 12/31/2010 '00', '01', '03', '08', '0A', '0C' Card Management Key '9B' 

After 12/31/2010 '00', '03', '08', '0A', '0C' 

Digital Signature Key '9C' After 12/31/2008 '07', '11', '14' 

Key Management Key '9D' After 12/31/2008 '07', '11', '14' 

Through 12/31/2010 '00', '01', '03', '06', '07', '08', '0A', '0C', '11' 

1/1/2011 Through 

12/31/2013 Card Authentication Key '9E' '00', '03', '06', '07', '08', '0A', '0C', '11' 

After 12/31/2014 '00', '03', '07', '08', '0A', '0C', '11' 
Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

Appendix A—Acronyms 

The following abbreviations and acronyms are used in this standard: 

2TDEA Two key TDEA 

3TDEA Three key TDEA 

AES Advanced Encryption Standard specified in [FIPS197]. 

CA Certification Authority 

CBEFF Common Biometric Exchange Formats Framework 

CHUID Card Holder Unique Identifier 

CRL Certificate Revocation List 

DES Data Encryption Standard 

ECB Electronic Codebook 

ECC Elliptic Curve Cryptography 

ECDSA Elliptic Curve Digital Signature Algorithm 

ECDH Elliptic Curve Diffie-Hellman 

FIPS Federal Information Processing Standards 

FISMA Federal Information Security Management Act 

ICAO International Civil Aviation Organization 

ITL Information Technology Laboratory 

NIST National Institute of Standards and Technology 

OCSP Online Certificate Status Protocol 

OID Object Identifier 

OMB Office of Management and Budget 

PIV Personal Identity Verification 

PKI Public Key Infrastructure 

PSS Probabilistic Signature Scheme 

RSA Rivest, Shamir, Adleman cryptographic algorithm 

SHA Secure Hash Algorithm 

SP Special Publication 

TDEA Triple Data Encryption Algorithm; Triple DEA 

 Page 13 
Special Publication 800-78-2 Cryptographic Algorithms and Key Sizes for PIV 

 Page 14 

Appendix B—References 

[FIPS186] Federal Information Processing Standard 186-3, Digital Signature Standard 

(DSS), June 2009. (See http://csrc.nist.gov) 

[FIPS197] Federal Information Processing Standard 197, Advanced Encryption Standard 

(AES), November 2001. (See http://csrc.nist.gov) 

[FIPS201] Federal Information Processing Standard 201-1, Change Notice 1, Personal 

Identity Verification (PIV) of Federal Employees and Contractors, March 2006. 

(See http://csrc.nist.gov) 

[MRTD] PKI for Machine Readable Travel Documents Offering ICC Read-Only Access 

Version - 1.1 Date - October 01, 2004. Published by authority of the Secretary 

General, International Civil Aviation Organization. 

[PKCS1] Jakob Jonsson and Burt Kaliski, "PKCS #1: RSA Cryptography Specifications 

Version 2.1", RFC 3447, February 2003. 

 [SP800-56B] NIST Special Publication 800-56B, Recommendation for Pair-Wise Key 

Establishment Schemes Using Integer Factorization Cryptography, August 2009. 

(See http://csrc.nist.gov) 

[SP800-56A] NIST Special Publication 800-56A, Recommendation for Pair-Wise Key 

Establishment Schemes Using Discrete Logarithm Cryptography, March 2007. 

(See http://csrc.nist.gov) 

[SP800-57(1)] NIST Special Publication 800-57, Recommendation for Key Management – Part 

1: General, March 2007. (See http://csrc.nist.gov) 

[SP800-73] NIST Special Publication 800-73-3, Interfaces for Personal Identity Verification, 

February 2010. (See http://csrc.nist.gov) 

[SP800-76] NIST Special Publication 800-76-1, Biometric Data Specification for Personal 

Identity Verification, January 2007. (See http://csrc.nist.gov)