> For the complete documentation index, see [llms.txt](https://sim-cards.learn-telecom.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sim-cards.learn-telecom.com/technology/algorithms.md).

# Algorithms

COMP128-1 – original algorithm with known weaknesses 

COMP128-2 – stronger algorithm which still clears the 10 rightmost bits of Kc 

COMP128-3 – same algorithm as COMP128-2 with all 64 bits of Kc generated 

COMP128-4 – based on the 3GPP (3rd Generation Partnership Project) algorithm “Milenage”, which uses AES