Abstract: In order to solve the problem that communication mechanism among cores cannot satisfy the high speed cryptographic operations' demand, this paper analyzed the communication characteristic of block, stream and hash cryptographic algorithms in the multi-core processor. Based on the multi-cluster structure, this paper proposed a new structure of shared memory, which could support communication among cores of random data width under 256bit. Besides, this paper proposed a way of email data synchronization which is based on improved spin lock. Each synchronization unit includes the function of add 1, . In the combination of shared memory and synchronization unit, this paper put forward the communication mechanism among cores based on shared memory. Based on the 65nm CMOS technology, the synthesis of shared memory and synchronization unit has been achieved, the result proves that our proposed the hardware area of communication mechanism among cores is small, the efficiency of data synchronization is high. The 256-bit data could be synchronized in two clock cycles among four processors, Comparing with other communication mechanisms, the communication mechanism get a better efficiency.