Call signs

• US 7,929,689 B2
• Filed: 06/30/2004
• Issued: 04/19/2011
• Est. Priority Date: 06/30/2004
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Cameron, Kim, Huitema, Christian François, Benaloh, Josh D.
• Primary Examiner(s): Patel; Nirav B
• Assistant Examiner(s): Moran; Randal D
• Application Number:
  US10/882,079
• Publication Number:
  US 20060005013A1
• Time in Patent Office: 2,484 Days
• Field of Search: 713/162, 380 28- 30
• US Class Current: 380/28
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/46 by designing passwords or checking the strength of passwords
• CPC Class Codes: H04L 9/3239 involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD

Abstract

A method of generating a call sign. A method of generating a call sign comprising determining a distinguished qualifier, finding a distinguished salt, and hashing the distinguished salt with the distinguished qualifier.

Claims

1. A method of generating a call sign comprising:

determining a distinguished qualifier, the distinguished qualifier comprising a public key of a public/private cryptographic key pair associated with a user;

iteratively testing salt values for at least a predetermined time and until a distinguished salt that when hashed with the distinguished qualifier causes a hash result to contain a predetermined pattern of at least a predetermined minimum number of bits is found;

hashing the distinguished salt with the distinguished qualifier to create a distinguished hash; and

encoding a predetermined number of bits of the distinguished, the predetermined number of bits being selected from a portion of the distinguished hash, the portion being selected at a location relative to the predetermined pattern, to create a call sign for the user;

wherein the above steps are performed by a computer.

2. The method of generating a call sign of claim 1, wherein finding the distinguished salt includes finding a salt that causes the hash result to contain the minimum number of the predetermined pattern of bits in a predetermined time.

3. The method of generating a call sign of claim 2, wherein the predetermined pattern of bits comprises a number of leading zeroes.

4. The method of generating a call sign of claim 3, further comprising retaining a number of bits, less than a total number of bits, following the leading zeroes.

5. The method of generating a call sign of claim 4, further comprising encoding the number of leading zeroes into an alphanumeric call sign zeroes digit.

6. The method of generating a call sign of claim 5, further comprising encoding the number of bits following the leading zeroes into a plurality of alphanumeric call sign digits.

7. The method of generating a call sign of claim 6, further comprising forming a call sign from the call sign zeroes digit and the plurality of alphanumeric call sign digits.

8. The method of generating a call sign of claim 4, wherein the encoding step comprises:

creating a binary number from a plurality of digits that follow the leading zeroes of the distinguished hash;

dividing the binary number into a plurality of five bits segments; and

encoding each of the five bit segments into corresponding alphanumeric characters.

9. The method of generating a call sign of claim 8, in which the binary number is forty five bits long.

10. The method of generating a call sign of claim 8, in which the alphanumeric zero character is in the most significant bit (MSB) positions.

11. The method of claim 1, wherein the distinguished qualifier comprises personalization information associated with the user, and wherein hashing of the distinguished salt with the distinguished qualifier to create a distinguished hash comprises:

hashing the public key to form a first hash result;

hashing the distinguished salt and the personalization information to form a second hash result; and

hashing the first and second hash results together to create the distinguished hash.

12. The method of claim 1, wherein the distinguished qualifier comprises personalization information associated with the user, and wherein hashing of the distinguished salt with the distinguished qualifier to create a distinguished hash comprises:

hashing the public key to form a first hash result; and

hashing the first hash result, the distinguished salt and the personalization information to create the distinguished hash.

13. A method of producing a cryptographic hash comprising:

forming a personalization information string associated with a person;

determining a minimum number of bits based on the time at which the cryptographic hash is produced;

finding a distinguished salt value that when hashed with the personalization information string and a public key of a public/private cryptographic key pair associated with the person, produces a hashed result that has a bit pattern with at least the minimum number of bits;

hashing the distinguished salt value with the personalization information string and the public key to generate a distinguished cryptographic hash; and

encoding a portion of the distinguished cryptographic hash as a plurality of alphanumeric characters representing a call sign for the person,

wherein the above steps are performed by a computer.

14. The method of producing a cryptographic hash of claim 13, in which the personalization information string includes a person'"'"'s name.

15. the method of producing a cryptographic hash of claim 13, in which the personalization information string includes a person'"'"'s e-mail address.

16. The method of producing a cryptographic hash of claim 13, in which the personalization information string includes a person'"'"'s company name.

17. The method of claim 13, wherein the minimum number of bits is determined as a function of a year in which the cryptographic hash is produced.

18. A method of producing a call sign comprising:

configuring a distinguished qualifier for a user, the distinguished qualifier comprising a public key of a public/private cryptographic key pair associated with the user and a personal identifier for the user;

finding a distinguished salt which when hashed with the distinguished qualifier generates a hash having a predetermined bit pattern with a size meeting a predetermined criteria in a predetermined portion of the hash, the criteria being such that the size increases as a function of the time at which the call sign is produced;

hashing the distinguished qualifier and the distinguished salt into an M bit hash;

selecting a predetermined number, L, bits from the M bit hash; and

encoding the size of the predetermined bit pattern into one digit of an alphanumeric call sign by using table lookup and encoding the L bits as other digits of the alphanumeric call sign;

wherein the above steps are performed by a computer.

19. The method of claim 18, wherein the criteria is a function of a year in which the call sign is produced.

20. The method of claim 18, wherein the distinguished qualifier comprises personalization information associated with the user, and wherein hashing of the distinguished salt and the distinguished qualifier into M bit hash comprises:

hashing the public key to form a first hash result;

hashing the distinguished salt and the personalization information to form a second hash result; and

hashing the first and second has results together to create the M bit hash.