When A Sponge Helps To Make Things Secure — And Light-weight
When can you get a hash function and also implement encryption? Well, you can when you have a sponge, and which stores and processes a permutation value. It was first introduced with SHA-3 and where we define a state size (S) of 1600 bits (Keccak-f[1600]). This state (S) is made up from r (rate) and c (capacity). The total bits in the state is thus 1,600 bits. With this we can either use it as a hashing method or as an authenticated encryption method:
A background on the sponge method is here.
The lightweight nature of the sponge method makes it perfect for a lightweight encryption and/or hashing method. One of these is ASCON, and which uses a duplex-sponge mode. For encryption, it can use 64-bit or 128-bit block sizes. Currently, ASCON is one of the finalists for a NIST-defined lightweight encryption method.
ASCON — Authenticated Encryption
ASCON [2] was designed by Christoph Dobraunig, Maria Eichlseder, Florian Mendel and Martin Schläffer from Graz University of Technology…
