可重构移位单元的设计与实现

Design and Implementation of Reconfigurable Shift Unit

在对称密码算法中移位操作使用频率非常高,尤其是在密钥生成中的应用。但各种算法之间的移位位宽和移位长度并不一致,所以现有的密码处理系统中还没有一个通用的移位单元支持所有对称密码算法的移位操作。本文在研究了多种对称密码算法的基础上,分析了高效灵活实现移位单元的方法,并提出了一种基于多级网络的可重构移位单元,它可以支持4/8/28/32/128-bit移位位宽以及可变移位长度的移位操作。此单元的设计与实现,不仅增强了密码处理单元的通用性,还使得可重构密码芯片的实现成为可能。

Shift operation is widely used in symmetric-key block ciphers. Since the data width and shift length are varied from different algorithms, there had not a general shift unit supporting all shift operations. In this paper, a high-performance and dynamic reconfigurable Shift Unit is presented, which provides full support for 4/8/28/32/128-bit data width shift operation. To boost up the adaptability, we adopt multilevel technique to realize arbitrary length shift. Compared with traditional schemes, the shift unit not only supports for all shift implementing modes, but also provides possibility for appearance of reconfigurable cryptographic system.