CONCEALING DEVICE AND CONCEALING METHOD

摘要

A security processing apparatus performs security processing in a MAC layer in a mobile communication system. The apparatus includes a mask generation unit generating a mask by using a security sequence number and a processing unit computing a logical operation on the mask and security target data to generate encrypted data. The security sequence number comprises a hyper frame number and a system frame number. The apparatus performs the security processing by using a transport block (TB) as one unit. The transport block is used as data transmission unit from a MAC layer to a physical layer per the unit time (TTI). Since HFN and SFN are used as the security sequence number, the security sequence number can be used uniformly over all RLC modes, and the out-of-synchronization of HFN can be avoided.