Confidential communication management

• US 9,942,034 B2
• Filed: 02/16/2016
• Issued: 04/10/2018
• Est. Priority Date: 02/13/2015
• Status: Active Grant

• Current Assignee: Visa International Service Association (Visa, Inc.)
• Original Assignee: Visa International Service Association (Visa, Inc.)
• Inventors: Le Saint, Eric, Bhattacharya, Soumendra
• Primary Examiner(s): Chai, Longbit
• Application Number:
  US15/045,052
• Publication Number:
  US 20160241389A1
• Time in Patent Office: 784 Days
• Field of Search: 713155
• CPC Class Codes: H04L 2463/062 applying encryption of the keys
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms

Abstract

Systems and methods are provided for confidential communication management. For instance, a server computer can include a protected server key identifier in a response message to a client computer. The protected server key identifier can include a server key identifier that identifies a server private key used to encrypt the response message. The client computer can pass the protected server key back in a subsequent request, so that the server computer can identify the proper server private key to use for decrypting the request message. In another example, a message may include encrypted protocol data (e.g., cipher suite) and separately encrypted payload data. The encrypted payload data can include a plurality of individually encrypted payload data elements.

Claims

1. A computer-implemented method, comprising:

receiving, by a server computer from a client computer, at least a portion of a request message including a protected server key identifier, a one-time client public key, and encrypted request data, wherein request data is encrypted using a request shared secret derived using a server public key and a one-time client private key associated with the one-time client public key;

decrypting, by the server computer, the protected server key identifier using a server identifier encryption key to obtain and to validate a server key identifier;

determining, by the server computer, a server private key associated with the validated server key identifier; and

decrypting, by the server computer, the encrypted request data using the server private key and the one-time client public key to obtain the request data associated with the portion of the request message.

2. The computer-implemented method of claim 1, wherein the server identifier encryption key is determined based on a default key pair comprising a default public key and a default private key.

3. The computer-implemented method of claim 1, wherein decrypting the encrypted request data comprises:

determining the request shared secret based on the server private key and the one-time client public key;

deriving a request session key based on the request shared secret; and

decrypting the encrypted request data using the request session key.

4. The computer-implemented method of claim 1, wherein the protected server key identifier is decrypted to obtain the server key identifier and a padding element, and the method further comprises validating the padding element before determining the server private key associated with the server key identifier.

5. The computer-implemented method of claim 1, further comprising:

for another request message including other encrypted request data, determining that another protected server key identifier does not map to an existing server private key and decrypting the other encrypted request data using a default server private key to obtain other request data.

6. The computer-implemented method of claim 1, further comprising:

determining a second server key identifier to be used in a next request from the client computer, the second server key identifier being associated with a second server private key;

encrypting the second server key identifier using the server identifier encryption key to determine a second protected server key identifier;

encrypting response data comprising the second protected server key identifier to generate encrypted response data; and

sending a response message including the encrypted response data to the client computer.

7. The computer-implemented method of claim 6, wherein encrypting the second server key identifier comprises encrypting a combination of the second server key identifier, a padding element, and a random element using the server identifier encryption key, the padding element being a constant value or a message authentication code (MAC) of the second server key identifier.

8. The computer-implemented method of claim 6, wherein the response message further comprises an obfuscated server public key corresponding to the second server private key.

9. The computer-implemented method of claim 6, wherein the request data includes a protected client key identifier and the response message includes the protected client key identifier, wherein protected client key identifier is used, by the client computer, to determine a client private key for decrypting the response message.

10. A computer-implemented method, comprising:

encrypting, by a sender computer, protocol data using one or more protocol encryption keys to generate encrypted protocol data, the protocol data indicating a cipher suite and/or a key identifier;

encrypting, by the sender computer, at least a portion of payload data using the protocol data and one or more payload encryption keys to generate encrypted payload data, wherein the one or more protocol encryption keys and the one or more payload encryption keys are determined based on one or more shared secrets, each generated using a receiver public key of a receiver computer and a sender private key of the sender computer, at least one of which is a one-time key; and

transmitting, by the sender computer to the receiver computer, a message comprising the encrypted payload data and the encrypted protocol data.

11. The computer-implemented method of claim 10, wherein the payload data comprises a plurality of payload elements and encrypting the payload data comprises encrypting each payload element of the plurality of payload elements using a corresponding payload encryption key to generate an encrypted payload element.

12. The computer-implemented method of claim 11, wherein the protocol data further comprises a plurality of data-protocol mappings respectively corresponding to the plurality of payload elements, each of the plurality of data-protocol mappings comprising a corresponding key identifier and an algorithm identifier, the corresponding key identifier identifying a payload encryption key used to encrypt the corresponding payload element, and the algorithm identifier identifying a cryptographic algorithm used to encrypt the corresponding payload element.

13. The computer-implemented method of claim 12, wherein each data-protocol mapping of the plurality of data-protocol mapping further comprises a message authentication code (MAC) of the corresponding payload element.

14. The computer-implemented method of claim 13, wherein the message further comprises a global MAC that is calculated based on the MACs corresponding to the plurality of payload elements.

15. A computer system comprising:

a memory that stores computer-executable instructions; and

one or more hardware processors configured to access the memory and execute the computer-executable instructions to implement a method comprising;

receiving a message comprising encrypted protocol data and encrypted payload data;

determining one or more protocol decryption keys;

decrypting the encrypted protocol data using the one or more protocol decryption keys to obtain protocol data indicating a cipher suite and/or a key identifier;

determining one or more payload decryption keys, wherein the one or more payload decryption keys and the one or more protocol decryption keys are determined based on one or more shared secrets, each generated using a sender public key and a receiver private key, at least one of which is a one-time key; and

decrypting the encrypted payload data using the protocol data and the one or more payload decryption keys to obtain payload data.

16. The computer system of claim 15, wherein the encrypted protocol data comprises an encrypted cipher suite, and wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

decrypting the encrypted cipher suite using a first protocol decryption key to obtain the cipher suite.

17. The computer system of claim 16, wherein the encrypted payload data comprises a plurality of encrypted payload elements and the encrypted protocol data further comprises a plurality of encrypted data-protocol mappings respectively corresponding to the plurality of encrypted payload elements, and wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

decrypting the plurality of encrypted data-protocol mappings using the cipher suite and a second protocol decryption key to obtain a plurality of data-protocol mappings.

18. The computer system of claim 17, wherein decrypting the encrypted payload data comprises decrypting an encrypted payload element of the plurality of encrypted payload elements by:

determining a data-protocol mapping from the plurality of data-protocol mappings that corresponds to the encrypted payload element;

selecting a payload decryption key for decrypting the encrypted payload element from the one or more payload decryption keys based at least in part on the data-protocol mapping;

identifying a decryption algorithm for decrypting the encrypted payload element based at least in part on the data-protocol mapping; and

decrypting the encrypted payload element using the selected payload decryption key and the identified decryption algorithm to obtain the payload element.

19. The computer system of claim 18, wherein the data-protocol mapping comprises a message authentication code (MAC) and decrypting the encrypted payload data further comprises validating the MAC.

20. A computer system comprising:

a memory that stores computer-executable instructions; and

one or more hardware processors configured to access the memory and execute the computer-executable instructions to implement a method comprising;

receiving, by a server computer from a client computer, at least a portion of a request message including a protected server key identifier, a one-time client public key, and encrypted request data, wherein request data is encrypted using a request shared secret derived using a server public key and a one-time client private key associated with the one-time client public key;

decrypting, by the server computer, the protected server key identifier using a server identifier encryption key to obtain and to validate a server key identifier;

determining, by the server computer, a server private key associated with the validated server key identifier; and

decrypting, by the server computer, the encrypted request data using the server private key and the one-time client public key to obtain the request data associated with the portion of the request message.

21. The computer system of claim 20, wherein the server identifier encryption key is determined based on a default key pair comprising a default public key and a default private key.

22. The computer system of claim 20, wherein decrypting the encrypted request data comprises:

determining the request shared secret based on the server private key and the one-time client public key;

deriving a request session key based on the request shared secret; and

decrypting the encrypted request data using the request session key.

23. The computer system of claim 20, wherein the protected server key identifier is decrypted to obtain the server key identifier and a padding element, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

validating the padding element before determining the server private key associated with the server key identifier.

24. The computer system of claim 20, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

for another request message including other encrypted request data, determining that another protected server key identifier does not map to an existing server private key and decrypting the other encrypted request data using a default server private key to obtain other request data.

25. The computer system of claim 20, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

determining a second server key identifier to be used in a next request from the client computer, the second server key identifier being associated with a second server private key;

encrypting the second server key identifier using the server identifier encryption key to determine a second protected server key identifier;

encrypting response data comprising the second protected server key identifier to generate encrypted response data; and

sending a response message including the encrypted response data to the client computer.

26. The computer system of claim 25, wherein encrypting the second server key identifier comprises encrypting a combination of the second server key identifier, a padding element, and a random element using server the identifier encryption key, the padding element being a constant value or a message authentication code (MAC) of the second server key identifier.

27. The computer system of claim 25, wherein the response message further comprises an obfuscated server public key corresponding to the second server private key.

28. The computer system of claim 25, wherein the request data includes a protected client key identifier and the response message includes the protected client key identifier, wherein protected client key identifier is used, by the client computer, to determine a client private key for decrypting the response message.

29. A computer system comprising:

a memory that stores computer-executable instructions; and

one or more hardware processors configured to access the memory and execute the computer-executable instructions to implement a method comprising;

encrypting, by a sender computer, protocol data using one or more protocol encryption keys to generate encrypted protocol data, the protocol data indicating a cipher suite and/or a key identifier;

encrypting, by the sender computer, at least a portion of payload data using the protocol data and one or more payload encryption keys to generate encrypted payload data, wherein the one or more protocol encryption keys and the one or more payload encryption keys are derived using one or more shared secrets, each generated using a receiver public key of a receiver computer and a sender private key of the sender computer, at least one of which is a one-time key; and

transmitting, by the sender computer to the receiver computer, a message comprising the encrypted payload data and the encrypted protocol data.

30. The computer system of claim 29, wherein the payload data comprises a plurality of payload elements and encrypting the payload data comprises encrypting each payload element of the plurality of payload elements using a corresponding payload encryption key to generate an encrypted payload element.

31. The computer system of claim 30, wherein the protocol data further comprises a plurality of data-protocol mappings respectively corresponding to the plurality of payload elements, each of the plurality of data-protocol mappings comprising a corresponding key identifier and an algorithm identifier, the corresponding key identifier identifying a payload encryption key used to encrypt the corresponding payload element, and the algorithm identifier identifying a cryptographic algorithm used to encrypt the corresponding payload element.

32. The computer system of claim 31, wherein each data-protocol mapping of the plurality of data-protocol mapping further comprises a message authentication code (MAC) of the corresponding payload element.

33. The computer system of claim 32, wherein the message further comprises a global MAC that is calculated based on the MACs corresponding to the plurality of payload elements.

34. A computer-implemented method comprising:

receiving a message comprising encrypted protocol data and encrypted payload data;

determining one or more protocol decryption keys;

decrypting the encrypted protocol data using the one or more protocol decryption keys to obtain protocol data indicating a cipher suite and/or a key identifier;

determining one or more payload decryption keys, wherein the one or more payload decryption keys and the one or more protocol decryption keys are determined based on one or more shared secrets, each generated using a sender public key and a receiver private key, at least one of which is a one-time key; and

decrypting the encrypted payload data using the protocol data and the one or more payload decryption keys to obtain payload data.

35. The computer-implemented method of claim 34, wherein the encrypted protocol data comprises an encrypted cipher suite, and wherein the method further comprises decrypting the encrypted cipher suite using a first protocol decryption key to obtain the cipher suite.

36. The computer-implemented method of claim 35, wherein the encrypted payload data comprises a plurality of encrypted payload elements and the encrypted protocol data further comprises a plurality of encrypted data-protocol mappings respectively corresponding to the plurality of encrypted payload elements, and wherein the method further comprises decrypting the plurality of encrypted data-protocol mappings using the cipher suite and a second protocol decryption key to obtain a plurality of data-protocol mappings.

37. The computer-implemented method of claim 36, wherein decrypting the encrypted payload data comprises decrypting an encrypted payload element of the plurality of encrypted payload elements by:

determining a data-protocol mapping from the plurality of data-protocol mappings that corresponds to the encrypted payload element;

selecting a payload decryption key for decrypting the encrypted payload element from the one or more payload decryption keys based at least in part on the data-protocol mapping;

identifying a decryption algorithm for decrypting the encrypted payload element based at least in part on the data-protocol mapping; and

decrypting the encrypted payload element using the selected payload decryption key and the identified decryption algorithm to obtain the payload element.

38. The computer-implemented method of claim 37, wherein the data-protocol mapping comprises a message authentication code (MAC) and decrypting the encrypted payload data further comprises validating the MAC.