Method and apparatus for encryption/authentication of data in energy metering applications
US5239584A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 26, 1991 |
| Grant date | Aug 24, 1993 |
| Priority date | — |
| Expiry date | Dec 26, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/80
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In one embodiment, the present invention is an encryption/decryption and authentication algorithm. The algorithm has three major steps. The first step is generating cipher text. The second step is generating the authentication field. The third step is encrypting or deciphering the appropriate data in the message. One byte of cipher text is generated for every byte of plain text contained in the message. After all the cipher text is generated, a four byte authentication field is generated using the last four bytes of cipher text. The message is then scanned for data fields which have been encrypted or are to be encrypted and the corresponding byte of cipher text replaces the message bytes. The encryption is accomplished by sending the cipher text instead of message text. To decipher the message, the algorithm operates in a reverse mode to replace the cipher text with the message text, i.e., the algorithm is a self-reversing process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.