We present a probabilistic public key cryptosystem which is secure unless the following worst-case lattice problem can be solved in polynomial time: "Find the shortest nonzero vector in an n dimensional lattice L where the shortest vector v is unique in the sense that any other vector whose length is ... more >>>

Public-key crypto Contact: dima@maths.univ-rennes1.fr Author: Dima Grigoriev Title: Public-key cryptography and invariant theory Abstract: Public-key cryptosystems are suggested based on invariants of group representations more >>>

We describe a public-key cryptosystem with worst-case/average case equivalence. The cryptosystem has an amortized plaintext to ciphertext expansion of $O(n)$, relies on the hardness of the $\tilde O(n^2)$-unique shortest vector problem for lattices, and requires a public key of size at most $O(n^4)$ bits. The new cryptosystem generalizes a conceptually ... more >>>