Paper 2026/1035

SoK: Rijndael-256

Anas Hlayhel, Intel (United States)

Setareh Sharifian, Intel (United States)

Alexander Tereschenko, Intel (Poland)

Abstract

Most symmetric modes of encryption that rely on PRP primitives are limited by the birthday bound over the block size (can’t encrypt more than $2^{n/2}$ blocks). This could be a severe limitation if current block width of 128 is used (can’t encrypt more than $2^{64}$ blocks) for cloud systems that transact a large amount of data. This limitation can be overcome by either realizing a mode of encryption based on a PRF (that doesn’t suffer from the birthday bound) or by using a wider block cipher like Rijndael−256 which allows us to encrypt $2^{128}$ blocks. In this paper, we focus on the wider block method as manifested in Rijndael−256. We survey theoretical and practical security for Rijndael-256. We also look at implementations of Rijndael−256 that take advantage of vectorized AES−NI which optimizes performance.

@misc{cryptoeprint:2026/1035,
      author = {Dessalegn Ayalneh and Anas Hlayhel and Setareh Sharifian and Alexander Tereschenko},
      title = {{SoK}: Rijndael-256},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/1035},
      year = {2026},
      url = {https://eprint.iacr.org/2026/1035}
}