Poly and Polyval hash functions compared for cryptographic use
Original title: Poly Versus Polyval
Poly is faster than Polyval for n=256 and 512 while Polyval is faster for n=128 in optimized implementations for NIST cryptographic accordions.
The paper revisits polynomial evaluation based hash functions Poly and Polyval over binary extension fields GF(2^n) with n=64k. It identifies irreducible polynomials for efficient usual and Montgomery reductions and provides optimized assembly code for n=128, 256, 512. Performance results show Polyval faster at n=128 and Poly faster at n=256 and 512, with relevance to the ongoing NIST process for cryptographic accordions.
- Poly avoids unnecessary bit reversals of GHASH.
- Poly uses usual reduction while Polyval uses Montgomery reduction.
- Optimized assembly implementations reported for n=128, 256, 512.
- Poly faster than Polyval for n=256 and 512.
- Cases n=128 and 256 relevant to NIST cryptographic accordions process.
From the original article
1 min read at arxiv.orgWe revisit the basic construction of polynomial evaluation based hash function, which we call Poly, over binary extension fields over $GF(2^n)$, where $n=64k$ and $k\geq 2$. Unlike GHASH, the NIST standard polynomial evaluation based hash function for $n=128$, Poly does not perform the unnecessary bit reversals of each $n$-bit block, and consequently is faster than GHASH.
By Kaushik Nath · arxiv.org
A short excerpt; the article and its images belong to the publisher. Summary, key facts and assessment above are AI-written from the article and can be wrong.