diff --git a/publications/Westerbaan2024.md b/publications/Westerbaan2024.md new file mode 100644 index 0000000..14d52cf --- /dev/null +++ b/publications/Westerbaan2024.md @@ -0,0 +1,31 @@ +--- +title: "X-Wing: The Hybrid KEM You've Been Looking For" +year: 2024 +location: "IACR Communications in Cryptology (Volume: 1, Issue: 1, March 2024)." +authors: + - Manuel Barbosa + - Deirdre Connolly + - João Diogo Duarte + - Aaron Kaiser + - Peter Schwabe + - Karolin Varner + - bas-westerbaan +doi: 10.62056/a3qj89n4e +related_interests: + - cryptography + - protocols +--- + +X-Wing is a hybrid key-encapsulation mechanism based on X25519 and +ML-KEM-768. It is designed to be the sensible choice for most applications. The +concrete choice of X25519 and ML-KEM-768 allows X-Wing to achieve improved +efficiency compared to using a generic KEM combiner. In this paper, we introduce the +X-Wing hybrid KEM construction and provide a proof of security. We show (1) that +X-Wing is a classically IND-CCA secure KEM if the strong Diffie-Hellman assumption +holds in the X25519 nominal group, and (2) that X-Wing is a post-quantum IND-CCA +secure KEM if ML-KEM-768 is itself an IND-CCA secure KEM and SHA3-256 is +secure when used as a pseudorandom function. The first result is proved in the ROM, +whereas the second one holds in the standard model. Loosely speaking, this means +X-Wing is secure if either X25519 or ML-KEM-768 is secure. We stress that these +security guarantees and optimizations are only possible due to the concrete choices +that were made, and it may not apply in the general case.