Patent ID: 9645793
Date: 2017-05-09
CPC Classifications: G06F

Claim:
1. A permutation generator circuit comprising a memory configured to store, for each number of a predetermined set of numbers, whether the number has already been included in a number sequence; a receiver configured to receive a random number; a determiner configured to select a number from those numbers of the set of numbers that have not yet been included in the number sequence as next element of the number sequence based on the random number; wherein the determiner is configured to perform a tree search based on the random number; wherein the determiner is configured to select, at each node of the tree, a sub-tree where it continues the search based on a bit of a bit representation of the random number; and an output configured to output the selected number as the next element of the number sequence; and wherein a time of an execution of at least one security relevant operation on a chip card is randomized based on the number sequence.