Secure telecommunications data transmission

• US 6,058,187 A
• Filed: 04/17/1997
• Issued: 05/02/2000
• Est. Priority Date: 04/17/1997
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Chen, Tsuhan
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US08/842,784
• Time in Patent Office: 1,111 Days
• Field of Search: 380/9, 380/21, 380/23, 380/25, 380/28, 380/49, 380/50, 380/59, 380/18, 380/30
• US Class Current: 713/170
• 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 9/14 using a plurality of keys or algorithms
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 7/12 for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal

Abstract

Secure data transmission apparatus comprises a data translator for translating an input string of signals, each signal having incomplete information for identifying an alphanumeric character, into a first encryption key. A data encrypter receives a first encryption key, a choice of encryption algorithm and a message and outputs an encrypted message according to the selected algorithm. The apparatus may be applied whenever the user is confronted with telecommunications apparatus that provides a limited input capability and no means for encrypting a message for transmission to an end user. In this manner, for example, a user may authenticate their name for display on caller identification plus name apparatus and the called party can be assured, before answering their line, that the call is from the party having the displayed name.

Claims

1. Secure data transmission apparatus for securing message data for transmission comprising:

a data receiver for receiving data representing a first key, an encryption algorithm choice and a message;

a database for storing a plurality of algorithms for encrypting data;

a processor, responsive to the data receiver, for encrypting the received message in accordance with a selected one of the plurality of algorithms; and

a data transmitter for outputting the encrypted message.

2. Apparatus according to claim 1 wherein said data transmitter further outputs data indicating said algorithm choice.

3. Apparatus according to claim 1 wherein said data transmitter further outputs a second key.

4. Apparatus according to claim 1 wherein said data transmitter further outputs data indicating said algorithm choice and a second key.

5. Apparatus according to claim 1 wherein said processor and said database are integrated as one unit and are secure.

6. Apparatus according to claim 1 wherein said database stores private keys and said data receiver receives dual tone multi-frequency signals, at least one signal representing one of a number and a plurality of letters, said processor receiving a sequence of said signals until a match is achieved with a unique, stored private key.

7. Apparatus according to claim 6 wherein said processor requires input of a signal sequence comprising all number or character elements of a private key for private key verification.

8. A method of securing data for transmission comprising the steps of:

receiving a first key;

receiving data representing a choice of encryption algorithm;

retrieving the chosen encryption algorithm;

receiving message data; and

encrypting the message data via the chosen encryption algorithm.

9. A method according to claim 8 further comprising the step of outputting data indicating said algorithm choice.

10. A method according to claim 8 further comprising the step of outputting a second key.

11. A method according to claim 8 further comprising the step of outputting data indicating said algorithm choice and a second key.

12. A method according to claim 8 further composing the step of securing an encryption processor and an associated database as one integrated unit.

13. A method according to claim 8 further comprising the steps of storing private keys and receiving dual tone multi-frequency signals, at least one signal representing one of a number and a plurality of letters, and receiving a sequence of said signals until a match is achieved with a unique, stored private key.

14. A method according to claim 13 further comprising the step of requiring input of a signal sequence comprising all number or character elements of a private key for private key verification.

15. Secure data transmission apparatus for translating an input string of received signals into a first encryption key comprising:

a secure database for storing a plurality of user encryption keys, each user key comprising a string of alphanumeric characters;

a data receiver for receiving the string of received signals, each received signal of the signal string providing incomplete data as to the identity of an alphanumeric character;

a processor for matching each received signal by received signal data representing the first encryption key with data representing the plurality of user encryption keys;

and a data generator for outputting data representing a selected one of the user encryption keys as the first encryption key when all the received signals match said selected one key.

16. A method for translating an input string of received signals into a first encryption key comprising the steps of:

receiving a string of received signals, each received signal of the signal string providing incomplete data as to the identity of an alphanumeric character;

storing a plurality of first encryption keys in a secure database;

matching each received signal with data of the first encryption keys of the secure database; and

outputting data representing a selected first encryption key when all the received signals match the first encryption key.

17. A method for decrypting data and authenticating a sender'"'"'s identity comprising the steps of:

receiving an encrypted message and data representing a choice of an algorithm;

decrypting said message according to the chosen algorithm;

authenticating the identity of the sender; and

generating data representing the decrypted message and authenticity of the message for display.

18. A method for decrypting data according to claim 17 wherein said decrypted message comprises sender identification data and said authenticity is indicated by one of a true and a false indicator.

19. Apparatus for decrypting data and authenticating a sender'"'"'s identity comprising:

a data receiver for receiving an encrypted message and data representing a choice of an algorithm;

a processor for decrypting said message according to the chosen algorithm and authenticating the identity of the sender; and

a data generator for generating data representing the decrypted message and authenticity of the message for display.

20. Apparatus for decrypting data according to claim 19 wherein said data generator generates decrypted message data comprising sender identification data and data authenticating the identity of the sender by one of a true and a false indicator.

21. Apparatus for translating an input string of received signals into a first encryption key, the apparatus comprising:

a secure database for storing a plurality of user encryption keys, each user key comprising a string of alphanumeric characters;

a data receiver for receiving the string of received signals, each received signal of the string of received signals providing incomplete data representing the identity of the string of alpha numeric characters, said string of alpha numeric characters representing at least one of the plurality of user encryption keys;

a processor for matching each received signal by received signal data representing the first encryption key with data representing said at least one of the plurality of user encryption keys; and

a data generator for outputting data representing a selected one of the user encryption keys as the first encryption key when all the received signals match said at least one of the plurality of user encryption keys.