Tamper resistant method and apparatus

• US 6,073,237 A
• Filed: 11/06/1997
• Issued: 06/06/2000
• Est. Priority Date: 11/06/1997
• Status: Expired due to Term

• Current Assignee: PayPal, Inc. (PayPal Holdings, Inc.), Paypal International Limited (PayPal Holdings, Inc.)
• Original Assignee: Cybercash, Inc. (VeriSign, Inc.)
• Inventors: Ellison, Carl
• Primary Examiner(s): Barron, Jr., Gilberto
• Application Number:
  US08/965,595
• Time in Patent Office: 943 Days
• Field of Search: 380/21, 380/24, 380/25, 380/279, 380/281, 380/283, 380/284, 705/66, 705/70, 705/64, 705/71, 705/67, 705/77, 713/171, 713/172, 713/183, 713/185
• US Class Current: 713/171
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06Q 20/085 involving remote charge determination or related payment systems
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G06Q 20/3829 involving key management
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• 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 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226

Abstract

A method for securing data in a tamper resistant fashion on a computer connected to a network. The presence of a user on a network is established using one protocol with routine operations conducted by the user on the network using a second protocol. Public and private key encryption is used to establish the validity of both the user and the server on the network user on the network. Keys are passed only after verification of the authenticity of the user on the network.

Claims

1. A tamper resistant method for securing a user'"'"'s data comprising:

initializing the presence of at least one user on a tamper resistant networked device using a first protocol; and

establishing routine operations by the user on the network using a second protocol, wherein the first protocol comprises;

the user sending a message to a network server;

the server verifying the presence of a user record;

the server creating a new record if an existing record does not exist;

the server sending a random challenge to the user;

the user signing the random challenge and sending the signed random challenge to the server;

the server verifying the user signature and thereafter generating a session key for the initialization protocol, the server further signing the session key and sending the key back to the user;

the user choosing a passphrase, encrypting the passphrase and sending the encrypted passphrase back to the server; and

the server generating a symmetric key, the symmetric key encrypted by the server and sent to the user.

13. The tamper resistant method for securing a user'"'"'s data of claim 1 wherein the user message further comprises the user'"'"'s public key, a transaction identifier, and a request for a new record.

14. The tamper resistant method for securing a user'"'"'s data of claim 1 wherein verifying the presence of a record by the server comprises using the user'"'"'s public key to determine if a record exists.

15. The tamper resistant method for securing a user'"'"'s data of claim 14 wherein verifying the presence of a record further comprises ignoring the user message if a record exists.

16. The tamper resistant method for securing a user'"'"'s data of claim 1 wherein the server sending the session key back to the user further comprises encrypting the session key with the public key if the user.

17. The tamper resistant method for securing a user'"'"'s data of claim 1 wherein the user encrypting the passphrase further comprises encrypting the passphrase with the session key.

18. The tamper resistant method for securing a user'"'"'s data of claim 1 wherein the sending of the symmetric key to the user further comprises encrypting the symmetric key using the session key.

2. A tamper resistant method for securing a user'"'"'s data comprising:

initializing the presence of at least one user on a tamper resistant networked device using a first protocol; and

establishing routine operations by the user on the network using a second protocol, wherein the second protocol comprises;

the user providing a passphrase to open a user workstation;

the user sending a first message to a network server identifying the presence of the user on the network;

the server looking up the record of the user to verify the user is permitted access;

the server generating a random challenge to the user;

the user signing the challenge and sending the signed challenge back to the server;

the server checking the signed challenge;

the server generating a temporary symmetric key and sending the temporary symmetric key back to the user, enciphered in a confidentiality key of the user'"'"'s known to the server;

the user receiving the temporary symmetric key;

the user generating a random challenge to the server, the user encrypting the random challenge using the temporary symmetric key;

the server signing the challenge from the user and encrypting the signed challenge using the temporary symmetric key;

the user verifying the signature on the challenge from the server;

the user encrypting the users passphrase using the temporary symmetric key and sending the encrypted passphrase to the server;

the server decrypting the encrypted passphrase and checking the passphrase against a record of the users passphrase stored in the server; and

, if that passphrase is correct;

the server sending a symmetric key to the user for subsequent use.

3. The tamper resistant method for securing a user'"'"'s data of claim 2 wherein the first user message comprises the user'"'"'s public key, and a transaction identifier.

4. The tamper resistant method for securing a user'"'"'s data of claim 2 wherein the server looking up the record of the user further comprises accessing records concerning the user which records are indexed according to the public key of the user.

5. The tamper resistant method for securing a user'"'"'s data of claim 4 wherein further comprising the server ignoring the message if no record of the user exists.

6. The tamper resistant method for securing a user'"'"'s data of claim 4 further comprising ignoring the message if the next permitted interaction time associated with the user is greater than the present server time.

7. The tamper resistant method for securing a user'"'"'s data of claim 2 further comprising the server sending a random challenge to the user only if the current time is greater than the next permitted interaction time associated with the user.

8. The tamper resistant method for securing a user'"'"'s data of claim 2 wherein the random challenge generated by the server sent to the user further comprises a transaction ID.

9. The tamper resistant method for securing a user'"'"'s data of claim 2 wherein the user signing the challenge message further comprises the user signing the message with the user'"'"'s private key.

10. The tamper resistant method for securing a user'"'"'s data of claim 2 wherein the checking of the signed challenge further comprises ignoring the user message if the signed challenge response is incorrect.

11. The tamper resistant method for securing a user'"'"'s data of claim 2 wherein the server generating a temporary symmetric key further comprises encrypting the temporary symmetric key using the public key of the user.

12. The tamper resistant method for securing a user'"'"'s data of claim 11 wherein the user receiving the temporary symmetric key further comprises the user decrypting the encrypted temporary symmetric key using the user'"'"'s private key.