B.2. Procedure Pre_Mul_P
3GPP55.251GEA5 and GIA5 algorithm specificationSpecification of the GEA5 and GIA5 encryption algorithms for General Packet Radio Service (GPRS)TS
This clause only available under licence.
See http://www.etsi.org/about/what-we-do/security-algorithms-and-codes/cellular-algorithm-licences.