Method for processing cryptographic data, involves randomly choosing derivative key from initial key to complement bit of initial key, and implementing derivation process based on selected key

摘要

The method involves randomly choosing a derivative key from an initial key (K) to complement a bit of the initial key (E4), and implementing a derivation process based on the selected key. A non-linear operation is applied by reading in a lookup table, where the non-linear operation is applied to a particular byte, and the reading is performed at the lookup table determined by the given byte. The derivative key is applied (E8) to message data by an exclusive OR operation. An independent claim is also included for a device for processing cryptographic data.