We introduce cryptographic primitives to the symbolic transition graph with the binary equivalence relation based on the CCS language with value-passing processes, which is designed for the description and analysis of security protocols. The STGR with cryptographic primitives, which is an extension of the STG, is applied to partition domains of conversations of security protocols that run in an infinite concurrent way, where principals possessing their relevant keys have received and transformed the message. The cryptographic primitives enable us to consider cryptographic issues on the principal conversations of security protocols in more detail. Our work results in a highly efficient solution to reduce computational complexities to prove safety properties of security protocols.