Public-Key Crypto and RFID Tags
We live in a world where little around us can be truely trusted. This includes the devices and the products that we use. So can we create devices which can tell us if we are using a fake medicine, or where we can truely trace products through a supply chain? So in these times of isolation, I’ve been turning to all those research papers I never quite was able to read properly, and so when a student asked me why elliptic curve methods for RFID was a light-weight crypto method, I dug out this paper [here]:
Within it, the authors outline that we generally struggle to apply public key encryption into RFID systems, as the complexity of the hardware and the battery drain is too high. The solution is to use an optimized ECC method using 131-bit and 139-bit prime numbers are used to reduce the complexity, and drain on the battery. For Bitcoin, for example, we use Secp256k1, and which uses a 256-bit prime number (2²⁵⁶–2³²–2⁹–2⁸–2⁷–2⁶–2⁴–1) and with Curve 25519 we use a prime number of 2²⁵⁵-19. In the paper, the authors propose a method with around 10,000 gates in order to implement the signing method for a device. Other researchers have implemented a 166-bit prime of to give 30,333 gates. There is thus a strong balance between…
