Database encryption and decryption circuit and method using subkeys
US4375579A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1980 |
| Grant date | Mar 1, 1983 |
| Priority date | — |
| Expiry date | Jan 30, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F21/6209
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An encryption and decryption circuit and method using subkeys which is therefore particularly useful for the encryption and decryption of database information. Each data field has a corresponding write key and a different read key. A database record is encrypted by multiplying each field by its corresponding write key and adding up all such products modulo the product of all read keys. The read keys must be prime numbers and the write keys must satisfy a certain relationship with respect to the read keys. A database record may have a single field decrypted by dividing the encrypted record by the read key for that field and taking the remainder. The security of each field may thereby be individually controlled without compromising the security of the entire record.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.