Encryption of low data content ATM cells
US5642421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1995 |
| Grant date | Jun 24, 1997 |
| Priority date | — |
| Expiry date | Sep 15, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2012/5673
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The security provided by encryption of ATM cells is enhanced by testing each cell for low data content level. If a cell has a low data content, its contents are nevertheless compressed and the resulting string is used to replace the original data. A length character and a randomly generated number which are added to the freed-up byte positions in the data field of the cell. The entire, modified data field is encrypted before the cell is transmitted. At a receiving system, a compression indicator is checked to determine whether the cell contains original or compressed data. If necessary, the length field and the random number are stripped and the remaining cell data is decompressed before the cell data is decrypted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.