Confidential communication management

• US 10,218,502 B2
• Filed: 03/08/2018
• Issued: 02/26/2019
• 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:
  US15/915,614
• Publication Number:
  US 20180198606A1
• Time in Patent Office: 355 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 example, a client computer can determine a client key pair comprising a client private key and a client public key. The client computer can further determine a protected server key identifier, identify a server public key associated with the protected server key identifier, and generating a shared secret using the server public key and the client private key. The client computer can further encrypt message data using the shared secret and sending, to a server computer, a message including the encrypted message data, the protected server key identifier, and the client public key. The protected server key identifier can be associated with the server computer and can be usable by the server computer to identify a server private key to be used in decrypting the encrypted message data.

Claims

1. A client computer 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;

determining a client key pair comprising a client private key and a client public key;

determining a protected server key identifier associated with a server computer, the protected server key identifier encrypted by a server identifier encryption key maintained by the server computer, the protected server key identifier usable by the server computer to validate a server key identifier associated with a server private key;

identifying the server public key associated with the protected server key identifier;

generating a shared secret using the server public key and the client private key;

encrypting message data using the shared secret to obtain encrypted message data; and

sending, to the server computer, a message including the encrypted message data, the protected server key identifier, and the client public key.

2. The client computer of claim 1, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

receiving, from the server computer, a response message including a second server public key and encrypted response data including a second protected server key identifier;

decrypting the encrypted response data using the client private key and the second server public key to obtain message data and the second protected server key identifier; and

storing the second protected server key identifier in association with the second server public key.

3. The client computer of claim 1, wherein the protected server key identifier includes padding data and a server key identifier, wherein the padding data is usable by the server to further validate the server key identifier.

4. The client computer of claim 1, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

determining a protected client key identifier associated with the client private key.

5. The client computer of claim 4, wherein the message data includes the protected client key identifier.

6. The client computer of claim 5, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

receiving, from the server computer, a response message including encrypted response data and the protected client key identifier.

7. The client computer of claim 6, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

associating the response message with the message based on the protected client key identifier.

8. The client computer of claim 6, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

determining the client private key associated with the protected client key identifier received in the response message;

decrypting the encrypted response data using the client private key and a server public key to obtain response data.

9. The client computer of claim 1, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

deriving a session key based on the shared secret; and

encrypting the message data using the session key.

10. The client computer of claim 1, 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 public key and encrypting the other encrypted request data using a default server public key to obtain other request data.

11. A server computer 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;

determining a server key identifier corresponding to a server private key and a server public key;

encrypting the server key identifier using a server identifier encryption key maintained by the server computer to obtain a protected server key identifier;

generating a shared secret using a client public key obtained from a client computer and the server private key;

encrypting message data using the shared secret to determine encrypted message data, wherein the message data includes the protected server key identifier; and

sending, to the client computer, a message including the encrypted message data, the protected server key identifier being decryptable using the server identifier encryption key, the protected server key identifier usable by the server computer to validate the server key identifier.

12. The server computer of claim 11, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

encrypting the server key identifier by encrypting a combination of the 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 server key identifier.

13. The server computer of claim 11, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

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

encrypting the message data using the message session key.

14. The server computer of claim 11, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

generating the protected server key identifier by encrypting a combination of the server key identifier and a padding element.

15. The server computer of claim 11, wherein the message further comprises an obfuscated server public key corresponding to the server private key.

16. The server computer of claim 11, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

receiving a request message from the client computer, wherein the request message includes a protected client key identifier associated with the client computer; and

including the protected client key identifier in the message sent to the client computer.

17. A client computer 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, from a server, a message including encrypted message data and a protected client key identifier, the protected client key identifier encrypted by a client identifier encryption key maintained by the client computer, the protected client key identifier usable by the client computer to validate a client key identifier associated with a client private key;

determining the client private key associated with the protected client key identifier;

decrypting the encrypted message data using the client private key and a server public key to obtain message data and a protected server key identifier; and

storing the protected server key identifier in association with the server public key.

18. The client computer of claim 17, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement, before receiving the message from the server:

determining the protected client key identifier;

encrypting request message data using the client private key and the server public key, wherein the message data includes the protected client key identifier; and

sending the request message data to the server.

19. The client computer of claim 17, wherein the one or more hardware processors are further configured to execute the computer-executable instructions to implement:

determining an order to process previous response messages before processing the message received from the server based on the value of the protected client key identifier.

20. The client computer of claim 17, wherein determining the client private key associated with the protected client key identifier includes:

decrypting the protected client key identifier to obtain a client key identifier;

determining the client private key based on the client key identifier.