Choosing Hash Functions

Overview

When selecting a cryptographic hash function for your application, several crucial factors need to be considered to ensure security and performance requirements are met. This guide will help you make informed decisions about hash function selection.

Selection Criteria

Security Level

• Choose hash functions that provide appropriate security levels for your use case
• For general cryptographic purposes, use at least 256-bit output hash functions
• For password hashing, select specialized algorithms like Argon2id or bcrypt
• Avoid deprecated hash functions like MD5 and SHA-1

Performance Requirements

• Consider the speed vs. security tradeoff
• For high-throughput applications, BLAKE3 or SHA-256 may be appropriate
• For password hashing, intentionally slow algorithms are preferred
• Test performance with your expected data volumes

Standards Compliance

• Check relevant standards and compliance requirements (FIPS, NIST, etc.)
• Consider industry-specific regulations
• Verify algorithm acceptance in your target environment
• Document your selection rationale for audit purposes

Implementation Availability

• Verify availability of trusted implementations in your programming language
• Check for active maintenance and security updates
• Consider hardware acceleration support
• Evaluate library documentation and community support