Pattern-free encryption

摘要

A method is described for defining a reserved pattern of symbols, receiving in a crypto-module an input stream including sequential input symbols, applying a cipher to the input stream in the crypto-module so as to generate an intermediate stream including sequential output symbols corresponding respectively to the input symbols, and converting the intermediate stream to an output stream from the crypto-module by comparing successive groups of the input symbols and the corresponding output symbols to the reserved pattern and, upon finding a match to the reserved pattern in a given group, substituting the input symbols in the group into the intermediate stream in place of the corresponding output symbols. Related hardware and systems are also described.

主权项

1. A method for data encryption, comprising:
defining a reserved pattern of symbols having a given length; receiving in a crypto-module an input stream comprising sequential input symbols; generating an intermediate stream of intermediate sequential symbols by applying a cypher to the input stream in the crypto-module, wherein each sequential symbol of the intermediate stream corresponds respectively to one of the sequential input symbols; comparing the reserved pattern to the sequential input symbols and intermediate sequential symbols in a sliding window of the given length in both the input and intermediate streams, wherein the reserved pattern is matched in the sliding window if for each of the symbols of the reserved pattern there is a match with a corresponding sequential symbol in at least one of the input or intermediate streams; generating an output stream from the intermediate stream, wherein for each matched reserved pattern, the corresponding sequential input symbols are substituted in place of the corresponding intermediate sequential symbols from the intermediate stream; and transmitting the output stream in a sequence of data records comprising respective headers and payloads.