Security on Plastics: Fake or Real?
Security on Plastics: Fake or Real?
复制标题
塑料安全：假的还是真的？
DOI：
10.13154/tches.v2019.i4.1-16
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
K. Myny
中科院分区：
文献类型：
--
作者：
N. Mentens;Jan Genoe;Thomas Vandenabeele;Lynn Verschueren;Dirk Smets;W. Dehaene;K. Myny
塑料箔上的电子设备，也被称为柔性电子产品，正在进入主流应用。在不久的将来，柔性电子标签可以嵌入到智能泡罩中，也可以作为柔性医疗贴片的主流技术。柔性电子产品的一项关键技术是基于薄膜晶体管，薄膜晶体管具有低成本制造的潜力，使其成为这些应用的理想候选者。然而，到目前为止，还没有人在柔性电子产品的设计中考虑数字安全性。两个主要的研究挑战出现。第一个挑战与电路的可靠性有关，当电路面积增加时，可靠性通常会降低。通过集成密码模块，我们探索了该技术的局限性，因为最小的轻量级块密码具有比迄今为止报道的柔性箔上最大的数字电路更大的面积。第二个挑战与密钥隐藏有关。芯片上相对较大的特征以及塑料上的电子芯片被用作裸管芯（即，它们未被封装）的事实使得容易读出所存储的密钥的值。因为还没有专用的非易失性存储器技术，所以在制造之后将数据写入柔性芯片的现有方法是基于利用激光或喷墨打印的线切割。然而，使用这些技术，在显微镜下“看到”密钥的值是非常容易的。我们提出了一种新的解决方案，使我们能够无形地编程后的关键制造。
Electronic devices on plastic foil, also referred to as flexible electronics, are making their way into mainstream applications. In the near future, flexible electronic labels can be embedded in smart blisters, but also used as mainstream technology for flexible medical patches. A key technology for flexible electronics is based on thin-film transistors, which have the potential to be manufactured at low cost, making them an ideal candidate for these applications. Yet, up to now, no-one is taking digital security into account in the design of flexible electronics.In this paper, we present, to our knowledge, the first cryptographic core on plastic foil. Two main research challenges arise. The first challenge is related to the reliability of the circuit, which typically decreases when the circuit area increases. By integrating cryptographic modules, we explore the limits of the technology, since the smallest lightweight block ciphers feature a larger area than the largest digital circuit on flex foil reported up to now. The second challenge is related to key hiding. The relatively large features on the chip and the fact that electronic chips on plastics are used as bare dies, i.e. they are not packaged, make it easy to read out the value of the stored secret key. Because there is no dedicated non-volatile memory technology yet, existing methods for writing data to the flexible chip after fabrication are based on wire cutting with a laser or inkjet printing. With these techniques, however, it is extremely easy to “see” the value of the secret key under a microscope. We propose a novel solution that allows us to invisibly program the key after fabrication.