Skip to main content

​
SHA256 Comparison

How SHA-256 compares to other cryptographic hash functions.

​
Quick Comparison Table

Hash FunctionOutput SizeSpeedSecurityUse Case
SHA-25632 bytesFast256-bitGeneral purpose, Bitcoin
Keccak-25632 bytesMedium256-bitEthereum
Blake2b1-64 bytesVery Fast512-bitHigh performance
RIPEMD-16020 bytesMedium160-bitBitcoin addresses
SHA-51264 bytesFast512-bitHigher security

​
SHA-256 vs Keccak-256

SHA-256:
  • NIST standard (FIPS 180-4)
  • Hardware acceleration widely available
  • Bitcoin, TLS/SSL, certificates
  • 3200 MB/s with SHA-NI
Keccak-256:
  • SHA-3 variant (original Keccak)
  • Used in Ethereum
  • Different padding than SHA-3
  • 1800 MB/s with optimizations
When to use SHA-256:
  • Bitcoin applications
  • General cryptography
  • Regulatory compliance required
  • Hardware acceleration important
When to use Keccak-256:
  • Ethereum smart contracts
  • EVM compatibility required
  • Address/topic calculation

​
SHA-256 vs Blake2

SHA-256:
  • Older, more established (2001)
  • NIST standardized
  • Hardware acceleration (SHA-NI)
  • 3200 MB/s accelerated, 500 MB/s software
Blake2:
  • Newer design (2012)
  • Faster in software (700 MB/s)
  • Variable output length
  • Not NIST standardized
When to use SHA-256:
  • Regulatory compliance needed
  • Hardware acceleration available
  • Standard conformance required
When to use Blake2:
  • Maximum software performance
  • Variable output length needed
  • No compliance requirements

​
SHA-256 vs SHA-512

Both are SHA-2 family members. SHA-256:
  • 32-byte output
  • Optimized for 32-bit platforms
  • More common in protocols
SHA-512:
  • 64-byte output
  • Faster on 64-bit platforms
  • Higher theoretical security
Performance (64-bit CPU with acceleration):
  • SHA-256: 3200 MB/s
  • SHA-512: 3400 MB/s (slightly faster!)
When to use SHA-256:
  • Standard 256-bit security sufficient
  • Smaller output preferred
  • Protocol specifies SHA-256
When to use SHA-512:
  • 512-bit security required
  • 64-bit platform
  • Larger output acceptable

​
Security Comparison

HashCollisionPreimageStatus
SHA-2562^1282^256✅ Secure
Keccak-2562^1282^256✅ Secure
Blake2b2^2562^512✅ Secure
SHA-1Broken2^160❌ Deprecated
MD5BrokenBroken❌ Insecure
All modern hash functions (SHA-256, Keccak-256, Blake2) provide adequate security.

​
Migration Guide

​
From MD5/SHA-1

// OLD (INSECURE)
import crypto from 'crypto';
const oldHash = crypto.createHash('md5').update(data).digest();

// NEW (SECURE)
import { SHA256 } from '@tevm/voltaire/crypto/sha256';
const newHash = SHA256.hash(data);

​
Choosing the Right Hash

Use SHA-256 when:
  • ✅ Bitcoin/blockchain applications
  • ✅ Digital signatures
  • ✅ Certificate fingerprints
  • ✅ Regulatory compliance required
  • ✅ Hardware acceleration available
Use Keccak-256 when:
  • ✅ Ethereum smart contracts
  • ✅ EVM compatibility needed
Use Blake2 when:
  • ✅ Maximum performance in software
  • ✅ Variable output length needed
  • ✅ No regulatory requirements

​
See Also