| 摘要 |
In order to save the storage space required for a secret key, the latter is subdivided into blocks, the blocks are then permutated and a permutation-linked index is stored. The index is significantly shortened in relation to the secret key. On the other hand, the secret key can be recovered from the index by determining the permutation in the index. The secret key is determined by means of the non-secret permutated blocks and the permutation. The invention also relates to an arrangement, i.e. a chip card, for coding and decoding. |
