b3sum
Compute and verify BLAKE3 cryptographic checksums.
TLDR
SYNOPSIS
b3sum [options] [file...]
DESCRIPTION
b3sum computes BLAKE3 cryptographic checksums. BLAKE3 is significantly faster than BLAKE2, MD5, SHA-1, and SHA-2, while maintaining high security. It's optimized for parallelism and can fully utilize modern CPU capabilities.The tool provides similar interface to md5sum and sha256sum but with much better performance.
PARAMETERS
-c, --check
Read BLAKE3 sums from the file(s) and verify them.--keyed
Keyed hashing mode; reads a 32-byte key from stdin.--derive-key context
Key derivation mode using the given context string.-l, --length bytes
Output length in bytes before hex encoding (default: 32).--seek offset
Start output at the given byte offset (default: 0).--num-threads n
Maximum number of threads to use.--no-mmap
Disable memory mapping of input files.--no-names
Omit filenames; output the hash only.--raw
Write the raw hash bytes to stdout instead of hex (single input only).--tag
Produce BSD-style checksum lines.--quiet
When verifying, do not print OK for each successfully verified file.
FEATURES
- Extremely fast (GBs per second)- Parallel processing- Unlimited output length- Tree hashing for verification- Keyed mode for authentication- Deterministic output
WORKFLOW
b3sum *.tar.gz > checksums.b3
# Verify
b3sum -c checksums.b3
# Hash stdin
cat largefile | b3sum
# Use multiple threads
b3sum --num-threads 8 hugefile.bin
INSTALL
CAVEATS
Relatively new algorithm (2020). Less widely adopted than SHA-256. Not suitable for password hashing (use argon2 instead). Requires recent software versions.
HISTORY
b3sum was released in 2020 alongside the BLAKE3 specification, created by Jack O'Connor and Samuel Neves as an evolution of BLAKE2 optimized for speed and parallelism.
