International Association
for Cryptologic Research

We examine the security of the 64-bit lightweight block cipher PRESENT-80 against related-key differential attacks. With a computer search we are able to prove that no related-key differential characteristic exists with probability higher than $2^{-64}$ for the full-round PRESENT-80.

To overcome the exponential (in the state and key sizes) computational complexity we use truncated differences, however as the key schedule is not nibble oriented, we switch to actual differences and apply early abort techniques to prune the tree-based search.

With a new method called extended split approach we are able to make the whole search feasible and we implement and run it in real time.

Our approach targets the PRESENT-80 cipher however, with small modifications can be reused for other lightweight ciphers as well.