Encryption protocol

• US 20030021419A1
• Filed: 07/11/2002
• Published: 01/30/2003
• Est. Priority Date: 07/11/2001
• Status: Active Grant

• Current Assignee: Anoto Group AB
• Original Assignee: Anoto Group AB
• Inventors: Romedahl, Lars, Hansen, Mads Dore, Thuvesholmen, Mikael, Sernbrant, Joakim
• Granted Patent: US 7,249,256 B2
• Time in Patent Office: Days
• US Class Current: 380/277
• CPC Class Codes: H04L 9/0637 Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM]
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees

Abstract

The present invention relates to a method, a system and a computer-readable medium storing computer-executable components in connection with transfer of information data to a recipient. The invention is based on the idea that generation of random number data and the calculation of digital signatures are performed before information data is accessible to a digital pen. Since asymmetric encryption of data is a demanding operation for said digital pen to perform in terms of processing power, a lot of time can be saved if the generation of random number data and asymmetric encryption of said random number data is performed in advance, when the pen is in an idle, non-communicating mode, for example during battery loading of the pen or when the pen is lifted from the position-coded paper. This alleviates delay times when the pen is in its communicating mode.

Claims

1. A method in connection with transfer of information data to a recipient, the method including the steps of:

generating a random number to be associated with an information data transmission, whenever non-repudiation of such information data transmission is to be provided, before the information data of that transmission is accessible;

signing said random number using a private key before said information data is accessible; and

sending said information data and said signed random number to said recipient, when said information data is accessible.

2. The method according to claim 1, including encrypting said random number using a public key before said information data is accessible.

3. The method according to claim 1 or 2, including the steps of:

concatenating said information data with said random number; and

evaluating the concatenated data in a hash function.

4. The method according to claim 3, including sending the signed and encrypted random number, the hash value of the concatenated data, and said information data to the recipient.

5. The method according to claim 3, including the steps of:

encrypting said information data using a symmetric key; and

sending the signed random number, the hash value of the concatenated data and the symmetrically encrypted data to the recipient.

6. The method according to claim 3, including the steps of:

evaluating said random number in a hash function;

encrypting said information data using the hash value of the random number as a symmetric key; and

sending the signed and encrypted random number, the hash value of the concatenated data, and the symmetrically encrypted data to the recipient.

7. The method according to claim 3, including the steps of:

evaluating said random number in a hash function;

CBC encrypting said concatenated data using the hash value of the random number as a key; and

sending the signed and encrypted random number, the hash value of the concatenated data and the encrypted data to the recipient.

8. The method according to any of the preceding claims, wherein said steps is performed by a digital pen, a paper look-up service or a service handler.

9. The method according to any of the preceding claims, wherein said recipient is a digital pen, a paper look-up service or a service handler.

19. A computer-readable medium storing computer-executable components for causing a unit to perform the steps recited in any one of claims 1-8 when the computer-executable components are run on microprocessor included by the unit.

10. A system for transfer of information data from a sender to a recipient, wherein the sender includes:

means arranged to generate a random number to be associated with an information data transmission, whenever non-repudiation of such information data transmission is to be provided, before the information data of that transmission is accessible;

means arranged to sign said random number using a private key before said information data is accessible; and

means arranged to send said information data and said signed random number to said recipient, when said information data is accessible.

11. The system according to claim 10, wherein the sender includes:

means arranged to encrypt said random number using a public key before said information data is accessible.

12. The system according to claim 10 or 11, wherein the sender includes:

means arranged to concatenate said information data with said random number; and

means arranged to evaluate the concatenated data in a hash function.

13. The system according to claim 12, wherein the sender includes:

means arranged to provide the signed and encrypted random number, the hash value of the concatenated data and said information data for transmission to the recipient.

14. The system according to claim 12, wherein the sender includes:

means arranged to encrypt said information data using a symmetric key; and

means arranged to provide the signed random number, the hash value of the concatenated data and the symmetrically encrypted data for transmission to the recipient.

15. The system according to claim 12, wherein the sender includes:

means arranged to evaluate said random number in a hash function;

means arranged to encrypt said information data using the hash value of the random number as a symmetric key; and

means arranged to provide the signed and encrypted random number, the hash value of the concatenated data and said information data for transmission to the recipient.

16. The system according to claim 12, wherein the sender includes:

means arranged to evaluate said random number in a hash function;

means arranged to CBC encrypt said concatenated data using the hash value of the random number as a key; and

means arranged to provide the signed and encrypted random number, the hash value of the concatenated data and the encrypted data for transmission to the recipient.

17. The system according to claims 10-16, wherein said sender is a digital pen, a paper look-up service or a service handler.

18. The system according to claims 10-17, wherein said recipient is a digital pen, a paper look-up service or a service handler.