摘要：

随着IP 核在SoC 设计中的大量使用,其版权问题得到广泛关注,通过植入硬件木马实现IP 核的版权保护是一个新的研究方向。针对其中植入木马激活时间短的问题,提出一种改进结构,使IP 核评估版本满足有效期长度的要求。将时序型硬件木马植入原始电路状态机的冗余状态中,选取电路中部分节点构成的序列作为木马状态的转移条件,木马激活后影响电路的正常功能,使IP 核的使用受到限制。仿真结果表明,通过合理调整状态数量及序列长度,能够在优化电路面积的同时有效延长木马的激活时间,当状态数为3、序列长度为4 时,该方法能够在电路面积减少0. 123% 的基础上使激活时间提高约120 倍。

关键词: IP 核, 硬件木马, 激活时间, 有效期, 状态机

Abstract:

With the widespread use of Intellectual Property ( IP ) in System-on-Chip ( SoC ) design, protection of hardware IP cores against piracy during evaluation becomes a major concern. Embedding a sequential hardware Trojan inside an IP is a new solution to protect the evaluation version of hardware IP. This paper proposes an advanced framework to lengthen the Trojan’s activation time which is the decisive factor of the expiry date of an IP. The sequential Trojan is inserted in the unused states of a Finite State Machine(FSM) in the target circuit and some rare nodes making up a sequence can be chosen as Trojan trigger conditions,and the normal function of the IP core is disturbed when the Trojan is activated. Simulation results demonstrate that the improved framework can effectively lengthen the activation time of the inserted Trojan by 120 times and simultaneously reduce the design overhead by 0. 123% when reasonably choosing the number of states as 3 and the length of sequence as 4.

Key words: IP core, hardware Trojan, activation time, expiry date, Finite State Machine(FSM)

中图分类号: 

• TP407