Encryption

• US 20030185398A1
• Filed: 06/10/2003
• Published: 10/02/2003
• Est. Priority Date: 10/10/2000
• Status: Active Grant

• Current Assignee: F-Secure Oyj
• Original Assignee: F-Secure Oyj
• Inventors: Hyppönnen, Ari
• Granted Patent: US 8,824,682 B2
• Time in Patent Office: Days
• US Class Current: 380/277
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

A method of enabling a user of a computer device to back-up an encryption key generated on the device, where the key is used to encrypt stored data, and the key is itself encrypted using a user password for storage on the device. The method comprises rendering the key into a form comprising a reduced length sequence of characters and displaying the reduced length sequence on a display of the device. The user is then able to write down the rendered key. The reduced length sequence may also be sent to a service provider in an SMS message, e-mail, or by voice dictation. In the event that the user password is lost, such that the encrypted key stored on the device cannot be unencrypted, encrypted data may still be accessed by the user entering the rendered key into the device.

Claims

1. A method of enabling a user of a computer device to back-up an encryption key generated on the device, the method comprising rendering the key into a form comprising a reduced length sequence of characters and displaying the reduced length sequence on a display of the device.

2. A method according to claim 1 and comprising:

encrypting other data stored in the device using the encryption key; and

storing the encryption key on the device in a form encrypted using a user password.

3. A method as claimed in claim 2 and comprising deleting both the original and the rendered encryption key from the memory of the computer device after the encrypted key has been generated and stored.

4. A method as claimed in any one of the preceding claims and comprising sending the rendered encryption key to a service provider.

5. A method as claimed in any one of the preceding claims, further comprising generating a checksum from the encryption key and storing the checksum on the computer device for later use in verifying an entered rendered encryption key.

14. A computer device arranged to perform the method of any one of the preceding claims.

15. A computer device according to claim 14, the computer device being a mobile wireless terminal.

6. A method of accessing encrypted information stored on a computer device, the method comprising:

entering an encryption key into the computer device, the key being rendered in a form comprising a reduced length sequence of characters;

decoding the rendered encryption key to generate a binary encryption key; and

unencrypting the encrypted information using the binary encryption key.

7. A method as claimed in claim 6, wherein the rendered encryption key is entered into the computer device using a keypad of the device.

8. A method as claimed in claim 6, wherein the rendered encryption key is entered into the device by way of a text message received from a service provider.

9. A method as claimed in any one of claims 6 to 8 and comprising verifying the encryption key prior to unencrypting the encrypted information by generating a checksum from said binary encryption key and comparing said checksum with a checksum stored on the computer device.

10. A method of enabling a user of a computer device to back-up an encryption key generated on the device, the method comprising rendering the key into a form comprising a reduced length sequence of characters and sending the reduced length sequence to a service provider.

11. A method according to claim 4 or 10 and comprising sending the rendered key to the service provider using a text messaging service of a mobile telecommunications network.

12. A method according to claim 4 or 10 and comprising sending the rendered key to the service provider by means of voice dictation.

13. A method according to claim 4, 10, 11 or 12 and comprising connecting the computer device to a WAP or www page maintained by the service provider to enable the user to provide identification information to the service provider.

16. A computer storage medium having encoded thereon a computer program for causing a computer device to:

render an encryption key into a form comprising a reduced length sequence of characters; and

display the reduced length sequence on a display of the device.

17. A computer storage medium having encoded thereon a computer program for causing a computer device to:

render an encryption key into a form comprising a reduced length sequence of characters; and

send the reduced length sequence to a service provider.