Classic McEliece encryption applicable for embedded devices!
MTG presents how post-quantum cryptography can be applied to embedded systems at the CARDIS 2020 conference.
CARDIS is a scientific conference specialized in security for embedded systems. During this event, MTG presented how to apply quantum-safe encryption methods on embedded systems.
The scientific work dealt with the question how storage requirements for the Classic McEliece public key could be reduced. Classic McEliece is often not considered for embedded devices, because with 255KB to over 1MB the sizes of public keys are usually much too large for the available memory. A possible solution is that such keys are generated externally and written to the flash memory of the device, but this only makes sense for limited application purposes. The space problem is solved by compact storage of the key pair. This is achieved by not explicitly storing the public key, but by adding a much smaller matrix to the private key. With this method, the public key can be generated piecewise "on-the-fly" without having to store it completely in memory.
To demonstrate the practical relevance, a Proof-of-Concept TLS implementation was implemented. It could be demonstrated that it is possible to run a Classic McEliece based Ephemeral Key Exchange for the mceliece348864 parameter set on an ARM Cortex-M4 board with 256 KB RAM. Although the public Classic McEliece key was already 255 KB in size, there was still enough memory left for the TLS stack, the TCP/IP stack and for the verification of SPHINCS+ signatures in the TLS handshake.
Image above (© Peter Gervais)