Encryption and authentication systems and methods

• US 20070174629A1
• Filed: 03/19/2007
• Published: 07/26/2007
• Est. Priority Date: 03/05/2001
• Status: Active Grant

• Current Assignee: Kioba Processing, LLC (IP Investments Group LLC)
• Original Assignee: Bolique Applications Ltd LLC (Intellectual Ventures LLC)
• Inventors: Suominen, Edwin
• Granted Patent: US 8,006,299 B2
• Time in Patent Office: Days
• US Class Current: 713/182
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 9/088 Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

Methods, apparatus, and systems are disclosed for, among other things, passphrase input using secure delay, passphrase input with characteristic shape display, user authentication with non-repeated selection of elements with a displayed set of elements, document authentication with embedding of a digital signature stamp within a graphical representation of the electronic document wherein the stamp comprises digits of a digital signature, and sub-hash computation using secure delay.

Claims

1. A passphrase input method comprising:

(a) accepting a plurality of user inputs of passphrase digits forming a sequence; and

(b) displaying a shape that is characteristic of the sequence.

2. The method of claim 1 wherein the sequence comprises a plurality of distinct consonant-vowel pairs.

3. The method of claim 1 wherein the shape comprises a plurality of line segments.

4. The method of claim 3 further comprising displaying the digits of the sequence in conjunction with the shape, wherein the line segments of the shape connect the displayed digits.

5. The method of claim 1 further comprising repeating parts (a) and (b) for multiple pluralities of passphrase digits.

6. The method of claim 5 wherein the multiple pluralities of passphrase digits form multiple sequences, the method further comprising displaying a plurality of shapes that are each characteristic of one the sequences.

7. An authentication method comprising:

(a) displaying a first set of selectable elements;

(b) accepting user selection of a selected element of the first set;

(c) displaying a second set of selectable elements that does not contain the selected element; and

(d) repeating parts (a) through (c) for a plurality of iterations.

8. The method of claim 7 wherein repeating for a plurality of iterations comprises, for each iteration subsequent to the first iteration, displaying as the first set of elements the previous iteration'"'"'s second set of elements.

9. The method of claim 8 further comprising displaying with the second set of elements a non-selectable element in a display position formerly occupied by the selected element.

10. The method of claim 7 wherein the selectable elements contain indicia of alphanumeric digits.

11. The method of claim 7 wherein user selection of a selected element is accepted via a mouse click.

12. A document authentication method comprising:

(a) generating a digital signature uniquely corresponding to an electronic document; and

(b) embedding a digital signature stamp within a graphical representation of the electronic document;

(c) wherein the stamp comprises digits of the digital signature and a distinctive graphical outline.

13. The method of claim 12 wherein the stamp is of a predetermined size.

14. The method of claim 12 wherein the distinctive graphical outline of the stamp has a plurality of line segments that lie along opposite sides of the stamp.

15. The method of claim 14 wherein the line segments form a continuous border that completely encloses the digits.

16. The method of claim 14 wherein the distinctive graphical outline of the stamp has a distinctive color.

17. The method of claim 12 further comprising requesting that a person who is digitally signing the document select a graphical region within the graphical representation of the document for application of the stamp.

18. A document authentication method comprising:

(a) responsive to a user printing a document to a virtual signature printer driver that has been installed as a printer device;

(1) generating a graphical representation of the document;

(2) obtaining authenticating information for applying the user'"'"'s digital signature to the document; and

(3) selecting a region within the graphical representation of the document for application of a digital signature stamp;

(b) computing a digital signature based on (1) the authenticating information and (2) data of the graphical representation of the document, exclusive of the selected region; and

(c) embedding within the graphical representation of the document, at the selected location, a digital signature stamp that comprises digits of the digital signature, thereby generating an authenticated graphical representation of the document.

19. The method of claim 18 wherein the stamp is of a predetermined size and further comprises a distinctive graphical outline that is of a distinctive color and has a plurality of line segments that lie along opposite sides of the stamp.

20. The method of claim 19 wherein the line segments form a continuous border that completely encloses the digits.

21. A passphrase entry method comprising:

(a) accepting user input of a plurality of passphrase elements; and

(b) performing a sequence of secure delay processing steps, each step generating a delayed output value from an initial value;

(c) wherein the initial value of each secure delay processing step is based on (1) a respective one of the passphrase elements and, for each secure delay processing step after the first, (2) a delayed output value from one of the other secure delay processing steps.

22. The method of claim 21 wherein part (b) begins before completion of part (a).

23. The method of claim 22 wherein the plurality of passphrase elements comprises alphanumeric characters.

24. The method of claim 23 wherein the plurality of passphrase elements further comprises one or more space characters.

25. The method of claim 23 wherein accepting user input comprises accepting keystrokes via a keyboard.

26. The method of claim 23 wherein accepting user input comprises accepting selections of graphical indicia via a pointing device.

27. A method comprising:

(a) applying a first hash code to a secure delay, thereby obtaining a delayed output; and

(b) computing a sub-hash from the delayed output.

28. The method of claim 27 further comprising repeating parts (a) and (b) for a plurality of iterations and successively displaying the sub-hash of each iteration, wherein the first hash code for each successive iteration is based on the delayed output of a previous iteration, whereby a user can visually compare the sub-hashes as they are computed.