Cryptographic device having reduced vulnerability to side-channel attack and method of operating same
US6724894B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 5, 1999 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Nov 5, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/56
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A cryptographic device and method of operation for encrypting messages. The device can be incorporated into a postage metering system to provide cryptographically secured postal indicia. The device and method provide increased security against side-channel attacks such as differential power analysis (DPA). An encryption key is transformed with a first function to generate temporary key as a function of a random number. A message is encrypted with the temporary key to generate a modified message. The modified message is transformed with a second function to generate an encryption. The encryption generated is identical to a direct encryption of the message with the untransformed key. The temporary key is changed frequently to protect against side-channel attacks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.