Method and apparatus for an adapted digital signature

• US 6,615,348 B1
• Filed: 04/16/1999
• Issued: 09/02/2003
• Est. Priority Date: 04/16/1999
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Gibbs, Benjamin K.
• Primary Examiner(s): Barroń; , Gilberto
• Assistant Examiner(s): Callahan, Paul E.
• Application Number:
  US09/293,131
• Time in Patent Office: 1,600 Days
• Field of Search: 380/28, 380/264, 713/153, 713/155, 713/162, 713/176, 713/190, 713/201
• US Class Current: 713/162
• CPC Class Codes: H04L 51/212 using filtering or selective blocking
• CPC Class Codes: H04L 63/0227 Filtering policies mail message filtering H04L51/212
• CPC Class Codes: H04L 63/126 the source of the received data

Abstract

A method and apparatus for an authenticated electronic userid comprising an adapted digital signature is provided. According to an aspect of the present invention, the adapted digital signature is generated using a secure hash function and an adaptation algorithm. According to one embodiment, a method for creating an adapted digital signature comprises retrieving an originator key, said originator key corresponding to a local userid; running a digital signature engine to create a digital signature, said digital signature based on at least said originator key and remote user information; retrieving a word from a word list, said word corresponding to at least a portion of said digital signature; and returning at least said word as said adapted digital signature.

Claims

1. A method for creating an adapted digital signature comprising:

retrieving an originator key, said originator key corresponding to a local userid;

running a digital signature engine to create a digital signature, said digital signature based on at least said originator key and remote user information;

retrieving a word from a word list, said word corresponding to at least a portion of said digital signature; and

returning at least said word as said adapted digital signature.

2. The method of claim 1, further comprising performing a boolean function on said digital signature to create a modified digital signature, and wherein said word is retrieved based upon said modified digital signature.

3. The method of claim 1, further comprising

generating a number; and

appending said number to said word form said adapted digital signature.

4. The method of claim 1, further comprising concatenating said adapted digital signature with said local userid and a domain name.

5. The method of claim 1, wherein running said digital signature engine includes performing a one-way hash function, said one-way hash function using at least said originator key and said remote user information, said one-way hash function generating a hash value, and said hash value being said digital signature.

6. A method for verifying an adapted digital signature comprising:

retrieving an originator key based on a first portion of address information;

generating an adapted digital signature, said act of generating comprising;

creating a digital signature based on at least said originator key and a second portion of said address information;

retrieving a word from a word list, said word corresponding to said digital signature; and

returning at least said word as said adapted digital signature;

comparing a third portion of said address information to said adapted digital signature; and

accepting said electronic message if said third portion of said address information and said adapted digital signature match.

7. The method of claim 6, further comprising:

testing said first portion of said address information to determine whether a local user identified by said receiver information employs authenticated message server services; and

accepting said electronic message if said local user does not employ said authenticated message server services.

8. The method of claim 6, wherein said second portion of said address information includes a sender domain name and said first portion of said address information includes a local userid.

9. The method of claim 6, wherein generating said adapted digital signature further comprises:

creating a modified digital signature from said digital signature, said modified digital signature created with a boolean function, and wherein said word is retrieved from said word list based upon said modified digital signature;

generating a number; and

appending said number to said word.

10. The method of claim 6, wherein creating said digital signature includes executing a one-way hash function, said one-way hash function using at least said originator key and said second portion of said address information, said one-way hash function generating a hash value, and said hash value being said digital signature.

11. A electronic message system comprising:

an authenticated message server, said authenticated message server configured to remove an inbound electronic message if an authenticated electronic userid cannot be verified, said inbound electronic message including address information; and

a mail host coupled to said authenticated message server;

wherein said authenticated message server is configured to remove said inbound electronic message by performing the acts of;

generating an adapted digital signature, said act of generating comprising;

creating a digital signature based on at least an originator key and a first portion of said address information;

retrieving a word from a word list, said word corresponding to said digital signature; and

returning said word as said adapted digital signature;

comparing a second portion of said address information to said adapted digital signature; and

rejecting said inbound electronic message if said second portion of said address information and said adapted digital signature do not match.

12. The electronic message system of claim 11, further comprising a mail exchanger coupled to said authenticated message server and configured to receive said inbound electronic message.

13. The electronic message system of claim 11, wherein said authenticated message server is configured to perform the act of parsing sender information and receiver information from said address information, said receiver information including a local userid and a second adapted digital signature.

14. The electronic message system of claim 11, wherein creating said digital signature includes executing a one-way hash function, said one-way hash function using at least said originator key and a portion of said address information, said one-way hash function generating a hash value, and said hash value being said digital signature.

15. The electronic message system of claim 11, wherein said act of generating said adapted digital signature further comprises performing a boolean function on said digital signature to create a modified digital signature, and wherein said word is retrieved based on said modified digital signature.

16. The electronic message system of claim 11, wherein said authenticated message server is further configured to perform the acts of:

generating a number; and

appending said number to said word to form said adapted digital signature.