Don't forget to lock your SIB: hiding instruments using P1687
Don't forget to lock your SIB: hiding instruments using P1687
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不要忘记锁定您的 SIB：使用 P1687 隐藏仪器
DOI：
10.1109/test.2013.6651903
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Micah Thornton
中科院分区：
文献类型：
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作者：
Jennifer Dworak;A. Crouch;John C. Potter;Adam Zygmontowicz;Micah Thornton
IEEE P1687是在测试、诊断、调试和板配置期间访问片上仪器的重要工具。然而，这些仪器中的大多数不应提供给该领域的最终用户。我们提出了一种方法，用于隐藏仪器在P1687网络，利用“锁定”段插入位（LSIB），只能打开时，预定义的值，对应于一个关键，存在于特定的位在链中。我们还引入了“陷阱”位，当错误的值写入陷阱的更新寄存器时，它可以通过永久锁定LSIB来进一步降低暴力攻击的有效性。只有全局重置才能让LSIB再次变得可操作。在本文中，我们调查的成本和效益的LSIB和陷阱在几种不同的配置，并表明，这些相对较小的修改P1687网络可以使无证文书的访问非常困难。
IEEE P1687 is a valuable tool for accessing on-chip instruments during test, diagnosis, debug, and board configuration. However, most of these instruments should not be available to an end user in the field. We propose a method for hiding instruments in a P1687 network that utilizes a “locking” segment insertion bit (LSIB) that can only be opened when pre-defined values, corresponding to a key, are present in particular bits in the chain. We also introduce “trap” bits, which can further reduce the effectiveness of brute force attacks by permanently locking an LSIB when an incorrect value is written to the trap's update register. Only a global reset will allow the LSIB to become operable again. In this paper, we investigate the cost and effectiveness of LSIBs and traps in several different configurations and show that these relatively small modifications to the P1687 network can make undocumented instrument access exceedingly difficult.