US Patent 11057205 Seed key expansion method and its uses

A seed key is expanded using a base primitive scheme. The first x bits of a seed key are used to determine a count number. These first x bits of the seed key are rotated from the front of the seed key to the back of the seed key. A pointer is then moved down the seed key a number of places corresponding to the count number. A specific bit pointed to by the pointer is then removed from the seed key and placed in the expanded key. After the deletion, the bit pointed to by the pointer is considered the front of the seed key and the process repeats until all the bits have been extracted and placed in the expanded key. These count numbers are also used to determine the specific bits to be removed from the plain text block and inserted into the cipher text block.