Abstract:
A method of authenticating a user includes providing a user key to an authentication authority, providing a transmission message from the authentication authority in response to the user key, providing a secret message using the transmission message, displaying the secret message to the user using a display screen, and providing a user response to the authentication authority in response to the user observing the secret message.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to authentication or verification of a person&#39;s identity for security purposes, and more particularly to a method for on-screen authentication using a secret visual message. 
       BACKGROUND 
       [0002]    An authentication factor is used to authenticate or verify a person&#39;s identity for security purposes. Two-factor authentication uses two different factors to authenticate the person. Using two factors as opposed to one delivers a higher level of authentication assurance. Using more than one factor is referred to as strong authentication. 
         [0003]    Currently, two-factor authentication can be achieved in several ways:
       1) Biometric—Using the unique physical features of a person as an authentication factor. The main drawback for biometric authentication is the privacy concerns of end-users. An end-user might not be willing and comfortable to allow banks and merchants to capture their biometric data such as a retina scan and fingerprint.   2) Security tokens—Smart cards, USB tokens, one-time-password (OTP) tokens are examples. OTP tokens have a liquid crystal display (LCD) screen which displays a pseudo-random number with 6 or more alphanumeric characters (numbers or combinations of letters and numbers, depending on the vendor and model). The pseudo-random number changes at pre-determined time intervals, usually every 60 seconds, but can also change at other time intervals or after a user event, such as the user pushing a button on the token. Tokens that change the pseudo-random number after a pre-determined time interval are referred to as time-based, and tokens that change the pseudo-random number after a user event are referred to as sequence-based (since the interval value is the current sequence number of the user events, i.e. 1, 2, 3, 4, etc.). When the pseudo-random number is combined with a personal identification number (PIN) or password, the resulting passcode has two factors of authentication (one from the PIN/password, another from the OTP token). Hybrid-tokens combine the capabilities of smartcards, USB tokens and OTP tokens.   3) Mobile Phones—two-factor authentication tools transform the user&#39;s mobile phone into a token device using SMS messaging or an interactive telephone call. The mobile phone becomes part of a two-factor, two-channel authentication mechanism. However, the SMS token device does have some operational problems and limitations, for example, an SMS OTP via mobile phone may not work properly due to being dependant on mobile phone providers, and SMS OTP may lead to increase phone bills.       
 
         [0007]    However, two-factor authentication a not pervasive because of cost effectiveness. Adding the second authentication factor increases implementation and maintenance costs. Most two-factor authentication systems are proprietary and currently charge an annual fee of $50 to $100 (USD) per user. In addition, hardware token deployment is logistically challenging, hardware tokens may get damaged or lost, and hardware token issuance in large industries such as banking or even within large enterprises needs to be managed. Moreover, end users with SMS token devices also face several problems such as when a token device is forgotten, misplaced, damaged, lost or the like. Another operational limitation with SMS messaging arises when a user might not be able to receive a SMS messages overseas. 
         [0008]    Therefore, there is a need to manage two-factor authentication that is convenient to use, requires relative low operational cost, secure to phishing site attacks and the like. 
       SUMMARY 
       [0009]    An aspect of the invention is a method of authenticating a user, comprising: providing a user key to an authentication authority; providing a transmission message from the authentication authority in response to the user key; providing a secret message using the transmission message; displaying the secret message to the user using a display screen; and providing a user response to the authentication authority in response to the user observing the secret message. 
         [0010]    The secret message can be a pseudo-random alphanumeric code and can be part of an (m,n)-threshold secret sharing scheme, wherein m is the number of parts required to recover a secret and n is the total number parts. 
         [0011]    The display screen can be a flat-panel display screen, an LCD screen and/or a mobile phone screen. 
         [0012]    The user response can be the secret message. 
         [0013]    The authentication authority can provide the user key to the user. In addition, the authentication authority can provide the transmission message to the user using the Internet, and the user can provide the user response to the authentication authority using the Internet. 
         [0014]    The method can be a two-factor authentication scheme, wherein the user key is the first factor and the user response is the second factor. 
         [0015]    An aspect of the invention is a method of authenticating a user, comprising providing a visual overlay from an authentication authority; providing a user key to the authentication authority; providing a background message from the authentication authority in response to the user key; displaying the background message on a display screen while the visual overlay is positioned over, aligned with and attached to the display screen; displaying a secret message to the user using the visual overlay and the background message; and providing a user response to the authentication authority in response to the user observing the secret message. 
         [0016]    The visual overlay can include a visual matrix pattern such as a pseudo-random visual matrix pattern. The visual overlay can also include a transparent medium, wherein the visual matrix pattern is non-transparent and the visual matrix pattern is printed on the transparent medium. The authentication authority can print the visual matrix pattern on the transparent medium, or alternatively, the user can print the visual matrix pattern on the transparent medium. 
         [0017]    The visual overlay can allow the user to observe a first selected portion of the display screen without allowing the user to observe a second selected portion of the display screen. In addition, the first selected portion of the display screen can display the secret message within the background message, the first selected portion of the display screen can be a window within the second selected portion of the display screen, the visual overlay can allow the user to observe a third selected portion of the display screen, and the user can enter the user response into the third selected portion of the display screen. 
         [0018]    The visual overlay can be a part of an (m,n)-threshold secret sharing scheme, wherein m is the number of parts required to recover a secret and n is the total number parts. In addition, the visual overlay can have substantially the same size as the display screen. 
         [0019]    The user response can be the secret message. 
         [0020]    The authentication authority can provide the user key to the user and provide the visual overlay to the user in response to the user key from the user. In addition, the authentication authority can provide the background message to the user using the Internet, and the user can provide the user response to the authentication authority using the Internet. 
         [0021]    The method can be a two-factor authentication scheme, wherein the user key is the first factor and the user response is the second factor. 
         [0022]    An aspect of the invention is method of authenticating a user, comprising providing a user key from an authentication authority to the user; then providing the user key from the user to the authentication authority a first time; providing a visual overlay from the authentication authority to the user in response to the user key provided the first time; then providing the user key from the user to the authentication authority a second time; providing a background message from the authentication authority to the user in response to the user key provided the second time; displaying the background message on a display screen facing the user while the visual overlay is positioned over, aligned with and attached to the display screen; displaying a secret message to the user using the visual overlay and the background message; and then providing a user response from the user to the authentication authority in response to the user observing the secret message. 
         [0023]    The encoded message can be displayed on the display screen and prompt the user to decode the encoded message, and the encoded message can be decoded in response to the user. 
         [0024]    The secret message can be a part of an (m,n)-threshold secret sharing scheme, wherein m is the number of parts required to recover a secret and n is the total number parts. 
         [0025]    The user response can be the secret message. 
         [0026]    The authentication authority can provide the user key to the user. In addition, the authentication authority can provide the encoded message to the user using the Internet, and the user can provide the user response to the authentication authority using the Internet. 
         [0027]    The method can be a two-factor authentication scheme, wherein the user key is the first factor and the user response is the second factor. 
         [0028]    An aspect of the invention is a method of authenticating a user, comprising providing a user key to the authentication authority; encoding a secret message at the authentication authority in response to the user key, thereby providing an encoded message; providing the encoded message from the authentication authority in response to the user key; decoding the encoded message, thereby providing the secret message; displaying the secret message on a display screen to the user in response to decoding the encoded message; and providing a user response to the authentication authority in response to the user observing the secret message on the display screen. 
         [0029]    An aspect of the invention is a method of authenticating a user, comprising providing a user key from an authentication authority to the user; then providing the user key from the user to the authentication authority; encoding a secret message at the authentication authority in response to the user key, thereby providing an encoded message; providing the encoded message from the authentication authority to the user in response to the user key from the user; displaying the encoded message on a display screen, thereby prompting the user to decode the encoded message; decoding the encoded message in response to the user observing the encoded message on the display screen, thereby providing the secret message; displaying the secret message on a display screen in response to decoding the encoded message; and providing a user response from the user to the authentication authority in response to the user observing the secret message on the display screen. 
         [0030]    An aspect of the invention is a method of authenticating a user, comprising providing a user key to an authentication authority; providing a transmission message from the authentication authority in response to the user key; providing a secret message using the transmission message; displaying the secret message to the user using a display screen; and providing a user response to the authentication authority in response to the user observing the encrypted secret message by using a mobile phone with the decryption key. 
         [0031]    An aspect of the invention is a method of authenticating a user, comprising providing a private key from an authentication authority; providing a user key to the authentication authority; providing a background message from the authentication authority in response to the user key; displaying the background message on a display screen while the mobile phone with the user private key is used to capture the background message on the display screen; displaying a secret message to the user using the mobile phone containing the private key and the background message; and providing a user response to the authentication authority in response to the user observing the secret message. 
         [0032]    An aspect of the invention is a method of authenticating a user, comprising providing a user key from an authentication authority to the user; then providing the user key from the user to the authentication authority a first time; providing a private key from the authentication authority to the user in response to the user key provided the first time; then providing the user key from the user to the authentication authority a second time; providing a background message from the authentication authority to the user in response to the user key provided the second time; displaying the background message on a display screen facing the user while the mobile phone is positioned over, aligned with and capture the barcode on the display screen; displaying a secret message to the user using the mobile phone; and then providing a user response from the user to the authentication authority in response to the user observing the secret message. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    In order that embodiments of the invention may be fully and more clearly understood by way of non-limitative examples, the following description is taken in conjunction with the accompanying drawings in which like reference numerals designate similar or corresponding elements, regions and portions, and in which: 
           [0034]      FIG. 1A  illustrates a block diagram of a registration and key distribution process in accordance with an embodiment of the invention; 
           [0035]      FIG. 1B  is a block diagram of a server with authority system that can be used in the system in accordance with an embodiment of the invention; 
           [0036]      FIG. 2A  illustrates a block diagram of a user login process in accordance with an embodiment of the invention; 
           [0037]      FIG. 2B  is a block diagram of a computer that can be used in the system in accordance with an embodiment of the invention; 
           [0038]      FIG. 3  illustrates a block diagram of a password reset process in accordance with an embodiment of the invention; 
           [0039]      FIG. 4A  illustrates a block diagram of a registration and mobile key distribution process in accordance with an embodiment of the invention; 
           [0040]      FIG. 4B  is a block diagram of a mobile phone that can be used in the system in accordance with an embodiment of the invention; 
           [0041]      FIG. 5  illustrates a block diagram of a user login process in accordance with an embodiment of the invention; 
           [0042]      FIG. 6  illustrates a key reset process in accordance with an embodiment of the invention; 
           [0043]      FIG. 7  is a block diagram that illustrates an activation process where a private key is generated and distributed securely to the end user mobile phone; 
           [0044]      FIG. 8  is a block diagram that illustrates a user login process in accordance with an embodiment of the invention; 
           [0045]      FIG. 9  is a block diagram illustrating a mobile key renewal process in accordance with an embodiment of the invention; and 
           [0046]      FIG. 10  is a block diagram illustrating a mobile key revocation process in accordance with an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0047]    Embodiments of the invention propose a method and system that are cost effective and easy to manage two-factor authentication using the enclosed on-screen authentication methods where the “token” is essentially a pseudo-random visual matrix pattern printed on normal transparency paper using normal printing devices.  FIG. 1-3  show block diagrams illustrating the registration and key distribution ( FIG. 1 ), the user login process ( FIG. 2 ), and the password reset process ( FIG. 3 ) in accordance with an embodiment of the invention. An embodiment of the invention is a technique that is different from typical tokens solution in that it can be use for secure multi-party login. Another embodiment of the invention is a mobile phone based application. 
         [0048]    Secret sharing scheme is a well researched area in cryptography proposed by Naor, M. and Shamir, A., “Visual cryptography”, In: LNCS, vol. 950, Springer-Verlag. pp. 1-12, incorporated herein by reference. The motivation for secret sharing is secure key management. In some situations, there is usually one secret key that provides access to many important files. If such a key is lost (e.g., the person who knows the key becomes unavailable, or the computer which stores the key is destroyed), then all the important files become inaccessible. The basic idea in secret sharing is to divide the secret key into pieces and distribute the pieces to different persons so that certain subsets of the persons can get together to recover the key. 
         [0049]    The general model for secret sharing is called an m-out-of-n scheme (or (m, n)-threshold scheme) for integers 1, m, and n. In the scheme, there is a sender (or dealer) and n participants. The sender divides the secret into n parts and gives each participant one part so that any m parts can be put together to recover the secret, but any m−1 parts reveal no information about the secret. The pieces are usually called shares or shadows. Different choices for the values of m and n reflect the tradeoff between security and reliability. A secret sharing scheme is perfect if any group of at most m−1 participant (insiders) has no advantage in guessing the secret over the outsiders. Therefore in a single party authentication mode, it is a (2, 2)-threshold scheme. In practice, the hidden secret could be any colored image which contains any graphics or characters from any language. This secret will be required as a second factor authentication during user login. 
         [0050]    With the reduction of cost in flat-screen display devices like LCD, Plasma TV, flat-screen CRT, and even mobile devices, it is becoming more pervasive items. 
         [0051]    Embodiments of the invention may include different schemes for effective and secured T-FA, for example by visual codes overlay, mobile token authentication, or the like. 
         [0052]    In an embodiment, the proposed scheme by visual codes overlay can be described in main phases: 1) registration and key distribution to users, 2) online user login and 3) password reset. 
         [0053]    For phase  1  as shown in  FIG. 1A , the authority  14  for online resources, for example a bank which provides Internet banking services, first needs to register and distribute a random key share to a user  12 . The server  15  is of the authority  14  is shown by dashed box, however, it will be appreciated that the components shown of authority system  14 , visual key generator  16  and database  18  may take different configurations, for example may be located remotely or separate from each other. Typically, the user provides registration information  10   a  such as identification, password and the like, and will be given a generated user ID and password generated by a key generator  16  and on top of that, the secret key shares printed on a transparent, physical medium (transparency)  24 . The visual key, S, is created  10   b  and with the visual key generator the store ID, password, S, etc. is stored  10   c  in the database  18 . This key could be sent  10   d  to the user through registered mail or even by electronic form for self-printing. The authority will keep a database  18  of all the user information: user ID|Password|key share.  FIG. 1B  is a block diagram of a server  15  with authority system module  14  that can be used in the system in accordance with an embodiment of the invention. The server may have a processor  11 , memory  13 , database  18 , interface  17 , visual key generator  16  and the like. It will be appreciated that the components shown in the server are for illustrative purposes and may take different arrangements and configurations, for example components such as the database, etc. may be located separately and/or remotely from the server. 
         [0054]    For phase  2 , as shown in system  10  of  FIG. 2A , when a user  12  tries to access online resources, the authority  14  will prompt  10   e  the user for user ID and password. Once this information is verified be correct, the system from the authority will generate  10   g  a pseudo-random share, S, based on a secret message will be displayed  10   h  as S on the screen and the user key share so that when the user overlays  10   h , 10   i  the user&#39;s self-kept visual token on the screen  22  over the secret message on the user&#39;s computer  20  on top of S, the secret message will be revealed. The database  18  is queried  10   f  to retrieve visual key share, S. The user then needs to key in this secret message and if it is correct, the user can gain access to the online resource. For multi-party login, at least n users need to be present with their key shares to overlay  24  and reveal the secret message before they can login.  FIG. 2B  is a block diagram of a computer  20  that can be used in the system in accordance with an embodiment of the invention. The computer is illustrative and may include processor  23 , memory  25 , interface  27  for interconnecting and communicating with other components of the system and the display  22  and input  21  such as a keyboard or keypad. 
         [0055]    For Phase  3 , as shown in  FIG. 3 , in the case of compromise or loss of the end-user secret token, the end-user could easily do a password reset with the authority. Basically, the end-user  12  will register  10   j  with the authority and ask for a new token. Authority system  14  will process the request and re-generate  10   k  with the key generator  16  a new visual key and update  10   l  the user ID|Password|key share entry in the database  18 . The new key can be convenient distributed  10   m  to the end user via registered mail, email etc. 
         [0056]    Due to the variants of display devices at the user&#39;s end, it may be difficult for end-user to align and overlay lens against the display screen to correctly display the secret message during authentication. To tackle this, an embodiment of the invention includes a few proposed techniques for easy on-screen authentication, for example: 
         [0000]    Technique 1: Easily adjustable on-screen lens size for end users
 
Technique 2: Redundancy in secret message structure
 
Technique 3: Dynamic screen size matching program
 
Technique 4: Pre-printed multi-size lens key
 
         [0057]    By using the lens key as a token, there are several advantages over traditional tokens solution, for example:
       1) Each lens key cost much less than a physical token   2) Lens key could be easy distributed to the end-user for self printing.   3) In case of any compromise to the lens key, a renewal key could be easily generated and distributed to the affected user.       
 
         [0061]    In an embodiment, the proposed scheme by mobile token authentication can be described in main phases: 1) user registration and mobile key distribution, 2) user login and authentication and 3) mobile key reset.  FIG. 4-10  provide another embodiment having a similar process for mobile token authentication. The system  50  of  FIG. 4  shows a server  55  of the authority  54  is shown by dashed box, however, it will be appreciated that the components shown of authority system  54 , mobile key generator  56  and database  58  may be in different configurations, for example located remotely or separate from each other. In this way, the user  52  provides  55   a  to the authority system  54  registration information such as ID, password, mobile number and the like. The mobile key generator  56  creates  50   b  mobile key, K. The registration information and mobile key K is stored  50   c  in database. The mobile key is then returned  50   d  via authority system  54  to be stored in the user&#39;s mobile phone.  FIG. 4B  is a block diagram of a mobile phone  62  that can be used in the system in accordance with an embodiment of the invention. The mobile phone  62  shown is illustrative and may comprise a processor  102 , memory  104  and an interface  106  and communications module for interacting and intercommunicating with other components of the system and display  80 , input  92  such as a camera, input  94  such as a keyboard or keypad, and other like components. 
         [0062]    In order for the mobile key to be transmitted securely (either via SMS, GPRS or any form of transportation protocol), it will be encrypted prior to the transmission. The encryption can be done either via a symmetric key algorithm or based on public key infrastructure (PKI) key-pairs. When a PKI system is used, the contents embedded in the visual code may be encrypted and digitally signed using the public and private keys of the authority system  54 . In this way, a 2-way verification of the service provider and service requestor can be ascertained securely, thereby increasing the security of the whole system. 
         [0063]    Similarly, the mobile key generated can either be based on a symmetric key algorithm or based on public key infrastructure (PKI) key-pairs. 
         [0064]    In cases where the user  52  needs to authenticate with more than one authority systems  54 , the same mobile application installed on his mobile phone can be used. In this case, multiple mobile keys specific to each of the authority systems would be stored securely on the mobile phone. The mobile key generator  56  creates new mobile key, K. 
         [0065]    The system  50  shown in  FIG. 5  shows authority system  54  with database  58  and random secret and visual code generator  70  having random secret generator module  72 , encryption module  74 , and visual code generator module  76  for producing visual code V  82 . The user  52  logins  50   e  via a computer  60  with ID, password and the like, and the database is queried  50   f  database  58  to retrieves mobile key, K, where the secret message m is generated  50   g  and encrypted with K to produce E as shown in  FIG. 5 . Encoded E is generated  50   h , 50   i  into visual code V  82 . The visual code V is displayed on screen  80  of computer and the user  52  uses a mobile device  62  to capture and decode visual code V to display  50   j  on mobile device visual code  84  on display of mobile device and of password  86  on display. The user uses  55   k  decoded password to login. 
         [0066]      FIG. 6  shows the process flow of the mobile key reset process of the system. The user  52  requests  501  for a mobile key reset. The authority creates  50   m  a new mobile key K. The store ID and other information such as ID, password, mobile number, K, and the like is stored  50   n  into the database  58 . The new mobile key is returned  50   o  via authority system  54  to be stored in user mobile phones. 
         [0067]    Visual lens or user overlay  24  is comparatively easier to replicate than physical tokens and it will be appreciated that the visual lens is more cost effective. 
         [0068]    An embodiment of the invention could be used as authentication means for scenario with these important characteristics: cross-order and mass authentication. 
         [0069]    Market segments and/or applications of embodiments of the invention in regards to two-factor authentication may include enterprise applications such as secure remote access, enterprise authentication, business to business (B2B) transactions, or the like; consumer applications such as online banking, electronic commerce, ISPs, or the like; government applications such as common authentication or the like. 
         [0070]    An embodiment of the invention is a technique that is different from typical tokens solution in that it can be use for secure login. 
         [0071]    In an embodiment, public-key cryptography is a method employed for secret communication between two parties without requiring an initial exchange of secret keys. It can also be used to create digital signatures. Public key cryptography enables secure transmission of information on the Internet. 
         [0072]    It is also known as asymmetric key cryptography because the key used to encrypt a message differs from the key used to decrypt it. In public key cryptography, a user has a pair of cryptographic keys—a public key and a private key. The private key is kept secret, while the public key may be widely distributed. Messages are encrypted with the recipient&#39;s public key and can only be decrypted with the corresponding private key. The keys are related mathematically, but the private key cannot be feasibly (ie, in actual or projected practice) derived from the public key. 
         [0073]    Symmetric cryptography uses a single secret key for both encryption and decryption. To use a symmetric encryption scheme, the sender and receiver must share a key in advance. Because symmetric encryption is less computationally intensive and requires less bandwidth, it is common to exchange a key using a key-exchange algorithm and transmit data using an enciphering scheme. 
         [0074]      FIG. 7  is a block diagram that illustrates an activation process  110  where a private key is generated and distributed securely to the end user  52  mobile phone  62 . The activation process involves downloading  110   a  signed midlet from website and generating  110   b  key pair. The passphrase is entered  110   c  that is received out of band to encrypt generated public key, where out of band is flexible depending on banks, other organizations and the like, through for example the ATM, user login to register their own or system automatically generated. The encrypted key is registered  110   d  with organization via GPRS, SMS, or the like. The system verifies user ID and decrypted to get user&#39;s generated public key that is to be stored  110   e  in the system&#39;s repository. 
         [0075]      FIG. 8  is a block diagram that illustrates a user login process  120  in accordance with an embodiment of the invention. The authentication process involves the user login  120   a  to the system, for example at server  55 , with login or registration information. The encrypted OTP is generated  120   b  in 2D barcode format for example. The system encrypts using the user&#39;s public key that is registered with the system. The user with image capturing device such as camera  94  on mobile phone  62  to take a snapshot  120   c  of the 2D bar to obtain OTP encrypted with the user&#39;s public key. The user  52  enters  120   d  the OTP and password onto the webpage, for example, and successfully logs in  120   e.    
         [0076]      FIG. 9  is a block diagram illustrating a mobile key renewal process  130  in accordance with an embodiment of the invention. A user  52  requests  130   a  for new passphrase, and a new key pair is generated  130   b . The passphrase is entered  130   c  to encrypt and generate the public key. The encrypted key is registered  130   d  with organisations for example via GPRS, SMS or the like. The system verifies the user ID and decrypts to obtain the user&#39;s generated public key and then stores  130   e  in the system&#39;s repository. 
         [0077]      FIG. 10  is a block diagram illustrating a mobile key revocation or loss of phone process  140  in accordance with an embodiment of the invention. The user  52  notifies  140   a  the administrator  142 . In another embodiment the user revokes  140   b  using other means such as automatic teller machines (ATM). The keys are revoked  140   c  by system  55  and renewal is disabled. In an embodiment, only re-registration is allowed. The user  32  repeats  140   d  registration process to register new keys. 
         [0078]    While embodiments of the invention have been described and illustrated, it will be understood by those skilled in the technology concerned that many variations or modifications in details of design or construction may be made without departing from the present invention.