SHA instruction set
A SHA instruction set is a set of extensions to the ARM, Power, RISC-V and x86 instruction set architecture which support hardware acceleration of the Secure Hash Algorithm (SHA) family.
ARM
[edit]SHA-1 and SHA-256 instructions appeared as optional features (FEAT_SHA1 and FEAT_SHA256) in the Arm V8.0 architecture introduced in 2011.[1] The instructions are:
- SHA-1:
SHA1C,SHA1H,SHA1M,SHA1P,SHA1SU0,SHA1SU1 - SHA-256:
SHA256H,SHA256H2,SHA256SU0,SHA256SU1
SHA-512 and SHA-3 instructions appeared as optional features (FEAT_SHA512 and FEAT_SHA3) in the Arm V8.2 architecture. [2] The instructions are:
- SHA-512:
SHA512H,SHA512H2,SHA512SU0,SHA512SU1 - SHA-3:
EOR3,RAX1,XAR,BCAX
A scalable vector extension (SVE) version of the SHA-3 instructions appeared as an optional feature (FEAT_SVE_SHA3) in the Arm V9.0 architecture. [3]
Power
[edit]Vector instructions for the Sigma functions for SHA-256 (vshasigmaw) and SHA-512 (vshasigmad) were added in the specification for Power ISA v.2.07[4] released in May 2013. The same instruction performs either Σ₀, Σ₁, σ₀ or σ₁ as described in the SHA-2 standard (FIPS-180-4) depending on parameters.
RISC-V
[edit]SHA2 instructions are part of the Zknh extension part of the RISC-V Cryptography Extensions Volume I: Scalar & Entropy Source Instructions[5] ratified in November 2021[6].
As SHA-512 is defined on 64-bit words, the instructions for SHA-512 differ in RV32 and RV64, with some RV32 instructions for SHA-512 split the elementary sigma operations in half in order to operate on a single 32-bit register.
The instructions are:
- SHA-256 (RV32 and RV64):
sha256sig0(SHA-256 σ₀),sha256sig1(SHA-256 σ₁),sha256sum0(SHA-256 Σ₀),sha256sum1(SHA-256 Σ₁) - SHA-512 (RV32):
sha512sig0h(high half of SHA-512 σ₀),sha512sig0l(low half of SHA-512 σ₀),sha512sig1h(high half of SHA-512 σ₁),sha512sig1l(low half of SHA-512 σ₁),sha512sum0r(SHA-512 Σ₀),sha512sum1r(SHA-512 Σ₁) - SHA-512 (RV64):
sha512sig0(SHA-512 σ₀),sha512sig1(SHA-512 σ₁),sha512sum0(SHA-512 Σ₀),sha512sum1(SHA-512 Σ₁)
x86 architecture processors
[edit]The original SSE-based extensions added four instructions supporting SHA-1 and three for SHA-256 and were specified in 2013 by Intel.[7] Instructions for SHA-512 were introduced in Arrow Lake and Lunar Lake in 2024.
- SHA-1:
SHA1RNDS4,SHA1NEXTE,SHA1MSG1,SHA1MSG2 - SHA-256:
SHA256RNDS2,SHA256MSG1,SHA256MSG2
The newer SHA-512 instruction set comprises AVX-based versions of the original SHA instruction set marked with a V prefix and these three new AVX-based instructions for SHA-512:
VSHA512RNDS2,VSHA512MSG1,VSHA512MSG2
AMD
[edit]All recent AMD processors support the original SHA instruction set:
Intel
[edit]The following Intel processors support the original SHA instruction set:
- Intel Goldmont[9] (2016) and later Atom microarchitecture processors.
- Intel Cannon Lake[10] (2018/2019), Ice Lake[11] (2019) and later processors for laptops ("mainstream mobile").
- Intel Rocket Lake (2021) and later processors for desktop computers.
The following Intel processors support the newer SHA-512 instruction set:
- Intel Arrow Lake and Lunar Lake processors.
References
[edit]- ↑ "The Armv8.0 architecture extension". Retrieved 2025-12-11.
- ↑ "The Armv8.2 architecture extension". Retrieved 2025-12-11.
- ↑ "The Armv9.0 architecture extension". Retrieved 2025-12-11.
- ↑ "Power ISA Version 2.07" (PDF). Power.org. 2013-05-15. Retrieved 2023-11-02.
- ↑ "Zknh - NIST Suite: Hash Function Instructions". Cryptography Extensions: Scalar & Entropy Source Instructions, Version 1.0.1. RISC-V International. Retrieved 4 September 2026.
- ↑ "Ratified Extensions". Retrieved 2025-02-12.
- ↑ "New Instructions Supporting the Secure Hash Algorithm on Intel® Architecture Processors". intel.com. Retrieved 2024-07-25.
- ↑ "Zen - Microarchitectures - AMD - WikiChip". en.wikichip.org. Retrieved 2024-07-25.
- ↑ "Goldmont - Microarchitectures - Intel - WikiChip". en.wikichip.org. Retrieved 2024-07-25.
- ↑ "Cannon Lake - Microarchitectures - Intel - WikiChip". en.wikichip.org. Retrieved 2024-07-25.
- ↑ "Ice Lake (client) - Microarchitectures - Intel - WikiChip". en.wikichip.org. Retrieved 2024-07-25.
External links
[edit]- Chapter 8 of "Intel Architecture Instruction Set Extensions Programming Reference" (PDF). Archived from the original (PDF) on 2013-09-29.