METHOD FOR APPLICATION AGAINST ATTACKS ON THIRD PARTY CHANNELS

摘要

1. A method of taking countermeasures against attacks on third-party channels, the method comprising executing a block cipher algorithm to mask intermediate variables, wherein the block cipher algorithm contains one or more non-linear functions, characterized in that at least one of the non-linear functions implemented using the in-place matching function. 2. The method according to claim 1, wherein the in-place matching function is a bit-random matching function in place (.3. The method according to claim 2, in which the bit-randomized matching function in place is defined as:, where is the address in memory, is a variable , which can be stored at an address in memory, and b is the value that is returned if the variable is equal to the actual data that is present at the address in memory; otherwise, addition b.4 is returned. The method according to claim 3, wherein Way according to claim 2, wherein said at least one of the non-linear functions contains a compare function defined by: where x is the first input variable of the compare function and y is the second input variable of the compare function, and b is the value that is returned if x is equal to y, and is the value that is returned if x is not equal to y, so the compare function can be implemented by: writing the variable x to the memory address; execution of the bit-randomized matching function in the place defined as: and returning. 6. The method of claim 1, wherein the non-linear function is contained in a SubByte operation. The method of claim 1, wherein the block cipher algorithm further comprises one or more lines