Encryption of applications to ensure authenticity
US6108784A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1997 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Apr 3, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/2107
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A software application is modified in a defined manner to prevent it being executable by a processor until the modified software application is decoded. Preferably, a sum of all of the bytes comprising a header of the software application (sufficiently small in size to be referred to as an "applet") is determined. In this embodiment, applet includes pseudo-code (p-code). Only the least most significant byte of the sum is used as a variable for modifying the p-code of the applet. Preferably, the variable is added to each byte of the p-code, except that only the first byte of a multi-byte p-code is thus modified. Alternatively, a different logical operator can be employed such as a subtract, AND, XOR, etc. for modifying the p-code. The modified program is then transferred to a portable pager that is also capable of maintaining personal information and executing small software applications. A processor in the pager device decodes p-code from the modified applet when needed during execution of the applet, by determining the variable that was used to modify the p-code and then subtracting the variable from p-code. The resulting p-code is then executable by the pager device. Modifying so…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.