Method and apparatus for usage protection of data files using split key and unique variable
US5208853A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1991 |
| Grant date | May 4, 1993 |
| Priority date | — |
| Expiry date | Sep 9, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F21/6209
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A split key encryption system to crypto-seal a data file comprising a method for unique variable entry (e.g., terminal serial number), random number generation, key storage device, encryption function for combining the unique variable and the random number to generate an encryption variable in an exclusive-OR function using a variable tap linear feedback shift register, and storage function for receiving the encryption variable and the unencrypted data file. A split key decryption system to unseal the crypto-sealed data file comprises a key storage device, terminal, terminal input, and storage function, with decryption again using an exclusive-OR function using a variable tap linear feedback shift register. A comparator allows use of the unencrypted data file only if the decrypted unique variable matches the terminal serial number.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.