| 摘要 |
When carrying out security related operations, uses exclusively multibit commands of operating program. Instead of bit commands, byte commands are used which trigger more complex signal flow than single bit operation. The data carrier prevents conclusions to be drawn on secret information from intercepted signals. Operating program consists of commands each triggering a specific operation. Each chip function has a defined command sequence. To make interception of information very difficult, multibit commands like copy or rotation commands are used in place of bit commands, like the bit shift. The commands processing multibit or a byte at the same time are more difficult to infer from as they produce complex signal flow. Also, for security relevant operation only commands are used, which trigger identical or very similar signal flow, where the processed data have no or very small influence on signal flow.
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