BLAKE (hash function)#BLAKE2

BLAKE was submitted to the NIST hash function competition by Jean-Philippe Aumasson, Luca Henzen, Willi Meier, and Raphael C.-W. Phan. In 2008, there were 51 entries. BLAKE made it to the final round consisting of five candidates but lost to Keccak in 2012, which was selected for the SHA-3 algorithm.

Like SHA-2, BLAKE comes in two variants: one that uses 32-bit words, used for computing hashes up to 256 bits long, and one that uses 64-bit words, used for computing hashes up to 512 bits long. The core block transformation combines 16 words of input with 16 working variables, but only 8 words (256 or 512 bits) are preserved between blocks.

It uses a table of 16 constant words (the leading 512 or 1024 bits of the fractional part of π), and a table of 10 16-element permutations:

σ[0] = 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

σ[1] = 14 10 4 8 9 15 13 6 1 12 0 2 11 7 5 3

σ[2] = 11 8 12 0 5 2 15 13 10 14 3 6 7 1 9 4

σ[3] = 7 9 3 1 13 12 11 14 2 6 5 10 4 0 15 8

σ[4] = 9 0 5 7 2 4 10 15 14 1 11 12 6 8 3 13

σ[5] = 2 12 6 10 0 11 8 3 4 13 7 5 15 14 1 9

σ[6] = 12 5 1 15 14 13 4 10 0 7 6 3 9 2 8 11

σ[7] = 13 11 7 14 12 1 3 9 5 0 15 4 8 6 2 10

σ[8] = 6 15 14 9 11 3 0 8 12 2 13 7 1 4 10 5

σ[9] = 10 2 8 4 7 6 1 5 15 11 9 14 3 12 13 0

The core operation, equivalent to ChaCha's quarter round, operates on a 4-word column or diagonal a b c d, which is combined with 2 words of message m[] and two constant words n[]. It is performed 8 times per full round:

j ← σ[r%10][2×i] // Index computations

k ← σ[r%10][2×i+1]

a ← a + b + (m[j] ⊕ n[k]) // Step 1 (with input)

d ← (d ⊕ a) >>> 16

c ← c + d // Step 2 (no input)

b ← (b ⊕ c) >>> 12

a ← a + b + (m[k] ⊕ n[j]) // Step 3 (with input)

d ← (d ⊕ a) >>> 8

c ← c + d // Step 4 (no input)

b ← (b ⊕ c) >>> 7

In the above, r is the round number (0–13), and i varies from 0 to 7.

The differences from the ChaCha quarter-round function are:

• The addition of the message words has been added.
• The rotation directions have been reversed.

"BLAKE reuses the permutation of the ChaCha stream cipher with rotations done in the opposite directions. Some have suspected an advanced optimization, but in fact it originates from a typo in the original BLAKE specifications", Jean-Philippe Aumasson explains in his "Crypto Dictionary".{{Cite book|last=Aumasson|first=Jean-Philippe|title=Crypto Dictionary: 500 Tasty Tidbits for the Curious Cryptographer|publisher=No Starch Press|year=2021|isbn=9781718501409}}

The 64-bit version (which does not exist in ChaCha) is identical, but the rotation amounts are 32, 25, 16 and 11, respectively, and the number of rounds is increased to 16.

Throughout the NIST hash function competition, entrants are permitted to "tweak" their algorithms to address issues that are discovered. Changes that have been made to BLAKE are: the number of rounds was increased from 10/14 to 14/16. This is to be more conservative about security while still being fast.

Hash values of an empty string:

{{color|green|BLAKE-224("")}} =

7dc5313b1c04512a174bd6503b89607aecbee0903d40a8a569c94eed

{{color|green|BLAKE-256("")}} =

716f6e863f744b9ac22c97ec7b76ea5f5908bc5b2f67c61510bfc4751384ea7a

{{color|green|BLAKE-384("")}} =

c6cbd89c926ab525c242e6621f2f5fa73aa4afe3d9e24aed727faaadd6af38b620bdb623dd2b4788b1c8086984af8706

{{color|green|BLAKE-512("")}} =

a8cfbbd73726062df0c6864dda65defe58ef0cc52a5625090fa17601e1eecd1b628e94f396ae402a00acc9eab77b4d4c2e852aaaa25a636d80af3fc7913ef5b8

Changing a single bit causes each bit in the output to change with 50% probability, demonstrating an avalanche effect:

{{color|green|BLAKE-512("The quick brown fox jumps over the lazy dog")}} =

1f7e26f63b6ad25a0896fd978fd050a1766391d2fd0471a77afb975e5034b7ad2d9ccf8dfb47abbbe656e1b82fbc634ba42ce186e8dc5e1ce09a885d41f43451

{{color|green|BLAKE-512("The quick brown fox jumps over the lazy do{{color|red|f}}")}} =

a701c2a1f9baabd8b1db6b75aee096900276f0b86dc15d247ecc03937b370324a16a4ffc0c3a85cd63229cfa15c15f4ba6d46ae2e849ed6335e9ff43b764198a

(In this example 266 matching bits out of 512 is about 52% due to the random nature of the avalanche.)

{{Infobox encryption method

| name = BLAKE2

| image =

| caption =

| designers = Jean-Philippe Aumasson, Samuel Neves, Zooko Wilcox-O'Hearn, Christian Winnerlein

| publish date =

| series =

| derived from = BLAKE

| derived to =

| related to =

| certification =

| digest size = up to 64 bytes (BLAKE2b); up to 32 bytes (BLAKE2s); arbitrary (BLAKE2X)

| structure =

| rounds = 10 or 12

| speed = 3.5 cpb on Core i5 (Ivy Bridge) for BLAKE2b{{cite web|url=https://blake2.net/acns/slides.html|title=BLAKE2 – an alternative to MD5/SHA-1}}

| cryptanalysis =

}}

BLAKE2 is a cryptographic hash function based on BLAKE, created by Jean-Philippe Aumasson, Samuel Neves, Zooko Wilcox-O'Hearn, and Christian Winnerlein. The design goal was to replace the widely used, but broken, MD5 and SHA-1 algorithms in applications requiring high performance in software. BLAKE2 was announced on December 21, 2012.{{cite web|url=http://lists.randombit.net/pipermail/cryptography/2012-December/003562.html|title=introducing BLAKE2 – an alternative to SHA-3, SHA-2 and MD5|first=Zooko|last=O'Whielacronx|date=21 December 2012|access-date=27 January 2016|archive-date=5 October 2016|archive-url=https://web.archive.org/web/20161005024333/https://lists.randombit.net/pipermail/cryptography/2012-December/003562.html|url-status=dead}} A reference implementation is available under CC0, the OpenSSL License, and the Apache License 2.0.{{cite web|url=https://github.com/BLAKE2/BLAKE2|title=BLAKE2 official implementations|website=GitHub|access-date=7 July 2019}}

BLAKE2b is faster than MD5, SHA-1, SHA-2, and SHA-3, on 64-bit x86-64 and ARM architectures.{{cite web|url=https://blake2.net/|title=BLAKE2|website=blake2.net}} Its creators state that BLAKE2 provides better security than SHA-2 and similar to that of SHA-3: immunity to length extension, indifferentiability from a random oracle, etc.{{cite journal |last1=Aumasson |first=Jean-Philippe |last2=Neves |first2=Samuel |last3=Wilcox-O’Hearn |first3=Zooko |last4=Winnerlein |first4=Christian |title=BLAKE2: simpler, smaller, fast as MD5 |url=https://eprint.iacr.org/2013/322.pdf |website=Cryptology ePrint Archive |publisher=IACR|year=2013 }}

BLAKE2 removes addition of constants to message words from BLAKE round function, changes two rotation constants, simplifies padding, adds parameter block that is XOR'ed with initialization vectors, and reduces the number of rounds from 16 to 12 for BLAKE2b (successor of BLAKE-512), and from 14 to 10 for BLAKE2s (successor of BLAKE-256).

BLAKE2 supports keying, salting, personalization, and hash tree modes, and can output digests from 1 up to 64 bytes for BLAKE2b, or up to 32 bytes for BLAKE2s. There are also parallel versions designed for increased performance on multi-core processors; BLAKE2bp (4-way parallel) and BLAKE2sp (8-way parallel).

BLAKE2X is a family of extendable-output functions (XOFs). Whereas BLAKE2 is limited to 64-byte digests, BLAKE2X allows for digests of up to 256 GiB. BLAKE2X is itself not an instance of a hash function, and must be based on an actual BLAKE2 instance. An example of a BLAKE2X instance could be BLAKE2Xb16MiB, which would be a BLAKE2X version based on BLAKE2b producing 16,777,216-byte digests (or exactly 16 MiB, hence the name of such an instance).{{Cite web|url=https://blake2.net/blake2x.pdf|title=BLAKE2X}}

BLAKE2b and BLAKE2s are specified in RFC 7693. Optional features using the parameter block (salting, personalized hashes, tree hashing, et cetera), are not specified, and thus neither is support for BLAKE2bp, BLAKE2sp, or BLAKE2X.{{cite IETF |title=The BLAKE2 Cryptographic Hash and Message Authentication Code (MAC) |rfc=7693 |last=Saarinen |first=M-J |last2=Aumasson|first2=J-P |date=November 2015 |publisher=IETF |access-date=4 December 2015 }}

BLAKE2b uses an initialization vector that is the same as the IV used by SHA-512. These values are transparently obtained by taking the first 64 bits of the fractional parts of the positive square roots of the first eight prime numbers.

IV₀ = 0x6a09e667f3bcc908 // Frac(sqrt(2))

IV₁ = 0xbb67ae8584caa73b // Frac(sqrt(3))

IV₂ = 0x3c6ef372fe94f82b // Frac(sqrt(5))

IV₃ = 0xa54ff53a5f1d36f1 // Frac(sqrt(7))

IV₄ = 0x510e527fade682d1 // Frac(sqrt(11))

IV₅ = 0x9b05688c2b3e6c1f // Frac(sqrt(13))

IV₆ = 0x1f83d9abfb41bd6b // Frac(sqrt(17))

IV₇ = 0x5be0cd19137e2179 // Frac(sqrt(19))

Pseudocode for the BLAKE2b algorithm. The BLAKE2b algorithm uses 8-byte (UInt64) words, and 128-byte chunks.

Algorithm BLAKE2b

Input:

M Message to be hashed

cbMessageLen: Number, (0..2¹²⁸) Length of the message in bytes

Key Optional 0..64 byte key

cbKeyLen: Number, (0..64) Length of optional key in bytes

cbHashLen: Number, (1..64) Desired hash length in bytes

Output:

Hash Hash of cbHashLen bytes

Initialize State vector h with IV

h_0..7 ← IV_0..7

Mix key size (cbKeyLen) and desired hash length (cbHashLen) into h₀

h₀ ← h₀ xor 0x0101kknn

where kk is Key Length (in bytes)

nn is Desired Hash Length (in bytes)

Each time we Compress we record how many bytes have been compressed

cBytesCompressed ← 0

cBytesRemaining ← cbMessageLen

If there was a key supplied (i.e. cbKeyLen > 0)

then pad with trailing zeros to make it 128-bytes (i.e. 16 words)

and prepend it to the message M

if (cbKeyLen > 0) then

M ← Pad(Key, 128) || M

cBytesRemaining ← cBytesRemaining + 128

end if

Compress whole 128-byte chunks of the message, except the last chunk

while (cBytesRemaining > 128) do

chunk ← get next 128 bytes of message M

cBytesCompressed ← cBytesCompressed + 128 increase count of bytes that have been compressed

cBytesRemaining ← cBytesRemaining - 128 decrease count of bytes in M remaining to be processed

h ← Compress(h, chunk, cBytesCompressed, false) false ⇒ this is not the last chunk

end while

Compress the final bytes from M

chunk ← get next 128 bytes of message M We will get cBytesRemaining bytes (i.e. 0..128 bytes)

cBytesCompressed ← cBytesCompressed+cBytesRemaining The actual number of bytes leftover in M

chunk ← Pad(chunk, 128) If M was empty, then we will still compress a final chunk of zeros

h ← Compress(h, chunk, cBytesCompressed, true) true ⇒ this is the last chunk

Result ← first cbHashLen bytes of little endian state vector h

End Algorithm BLAKE2b

The Compress function takes a full 128-byte chunk of the input message and mixes it into the ongoing state array:

Function Compress

Input:

h Persistent state vector

chunk 128-byte (16 double word) chunk of message to compress

t: Number, 0..2¹²⁸ Count of bytes that have been fed into the Compression

IsLastBlock: Boolean Indicates if this is the final round of compression

Output:

h Updated persistent state vector

Setup local work vector V

V_0..7 ← h_0..7 First eight items are copied from persistent state vector h

V_8..15 ← IV_0..7 Remaining eight items are initialized from the IV

Mix the 128-bit counter t into V₁₂:V₁₃

V₁₂ ← V₁₂ xor Lo(t) Lo 64-bits of UInt128 t

V₁₃ ← V₁₃ xor Hi(t) Hi 64-bits of UInt128 t

If this is the last block then invert all the bits in V₁₄

if IsLastBlock then

V₁₄ ← V₁₄ xor 0xFFFFFFFFFFFFFFFF

Treat each 128-byte message chunk as sixteen 8-byte (64-bit) words m

m_0..15 ← chunk

Twelve rounds of cryptographic message mixing

for i from 0 to 11 do

Select message mixing schedule for this round.

BLAKE2b uses 12 rounds, while SIGMA has only 10 entries.

S_0..15 ← SIGMA[i mod 10] Rounds 10 and 11 use SIGMA[0] and SIGMA[1] respectively

Mix(V₀, V₄, V₈, V₁₂, m[S₀], m[S₁])

Mix(V₁, V₅, V₉, V₁₃, m[S₂], m[S₃])

Mix(V₂, V₆, V₁₀, V₁₄, m[S₄], m[S₅])

Mix(V₃, V₇, V₁₁, V₁₅, m[S₆], m[S₇])

Mix(V₀, V₅, V₁₀, V₁₅, m[S₈], m[S₉])

Mix(V₁, V₆, V₁₁, V₁₂, m[S₁₀], m[S₁₁])

Mix(V₂, V₇, V₈, V₁₃, m[S₁₂], m[S₁₃])

Mix(V₃, V₄, V₉, V₁₄, m[S₁₄], m[S₁₅])

end for

Mix the upper and lower halves of V into ongoing state vector h

h_0..7 ← h_0..7 xor V_0..7

h_0..7 ← h_0..7 xor V_8..15

Result ← h

End Function Compress

The Mix function is called by the Compress function, and mixes two 8-byte words from the message into the hash state. In most implementations this function would be written inline, or as an inlined function.

Function Mix

Inputs:

V_a, V_b, V_c, V_d four 8-byte word entries from the work vector V

x, y two 8-byte word entries from padded message m

Output:

V_a, V_b, V_c, V_d the modified versions of V_a, V_b, V_c, V_d

V_a ← V_a + V_b + x with input

V_d ← (V_d xor V_a) rotateright 32

V_c ← V_c + V_d no input

V_b ← (V_b xor V_c) rotateright 24

V_a ← V_a + V_b + y with input

V_d ← (V_d xor V_a) rotateright 16

V_c ← V_c + V_d no input

V_b ← (V_b xor V_c) rotateright 63

Result ← V_a, V_b, V_c, V_d

End Function Mix

Hash values of an empty string:

{{color|green|BLAKE2s-224("")}} =

1fa1291e65248b37b3433475b2a0dd63d54a11ecc4e3e034e7bc1ef4

{{color|green|BLAKE2s-256("")}} =

69217a3079908094e11121d042354a7c1f55b6482ca1a51e1b250dfd1ed0eef9

{{color|green|BLAKE2b-384("")}} =

b32811423377f52d7862286ee1a72ee540524380fda1724a6f25d7978c6fd3244a6caf0498812673c5e05ef583825100

{{color|green|BLAKE2b-512("")}} =

786a02f742015903c6c6fd852552d272912f4740e15847618a86e217f71f5419d25e1031afee585313896444934eb04b903a685b1448b755d56f701afe9be2ce

Changing a single bit causes each bit in the output to change with 50% probability, demonstrating an avalanche effect:

{{color|green|BLAKE2b-512("The quick brown fox jumps over the lazy dog")}} =

a8add4bdddfd93e4877d2746e62817b116364a1fa7bc148d95090bc7333b3673f82401cf7aa2e4cb1ecd90296e3f14cb5413f8ed77be73045b13914cdcd6a918

{{color|green|BLAKE2b-512("The quick brown fox jumps over the lazy do{{color|red|f}}")}} =

ab6b007747d8068c02e25a6008db8a77c218d94f3b40d2291a7dc8a62090a744c082ea27af01521a102e42f480a31e9844053f456b4b41e8aa78bbe5c12957bb

• Argon2, the winner of the Password Hashing Competition, uses BLAKE2b
• Chef's Habitat deployment system uses BLAKE2b for package signing{{Cite web|url=https://docs.chef.io/habitat/|title=About Chef Habitat|website=docs.chef.io}}
• FreeBSD Ports package management tool uses BLAKE2b
• GNU Core Utilities implements BLAKE2b in its b2sum command{{cite web|url=https://github.com/coreutils/coreutils/tree/master/src/blake2|title=coreutils/src/blake2/|website=github.com}}
• IPFS allows use of BLAKE2b for tree hashing
• librsync uses BLAKE2b{{cite web|url=https://github.com/librsync/librsync/tree/master/src/blake2|title=librsync/src/blake2/|website=github.com}}
• Noise (cryptographic protocol), which is used in WhatsApp includes BLAKE2 as an option.{{Cite web|url=https://www.whatsapp.com/security/WhatsApp-Security-Whitepaper.pdf|title=WhatsApp Security Whitepaper}}{{Citation needed|reason=WhatsApp Security Whitepaper doesn't support claim.|date=July 2019}}
• RAR archive format version 5 supports an optional 256-bit BLAKE2sp file checksum instead of the default 32-bit CRC32; it was implemented in WinRAR v5+{{cite web|url=http://rarsoft.com/rarnew.htm|title=WinRAR archiver, a powerful tool to process RAR and ZIP files|website=rarsoft.com}}
• 7-Zip (in order to support the RAR archive format version 5{{cite web|url=https://sourceforge.net/p/sevenzip/feature-requests/1489/#320e|title=Igor Pavlov's response to a user request for BLAKE3 support in 7-Zip|website=sourceforge.net}}) can generate the BLAKE2sp signature for each file in the Explorer shell via "CRC SHA" context menu, and choosing '*'
• rmlint uses BLAKE2b for duplicate file detection{{Cite web|url=https://rmlint.readthedocs.io/en/latest/rmlint.1.html|title=rmlint — rmlint (2.8.0 Maidenly Moose) documentation|website=rmlint.readthedocs.io}}
• WireGuard uses BLAKE2s for hashing{{Cite web|url=https://www.wireguard.com/papers/wireguard.pdf|title=WireGuard: Next Generation Kernel Network Tunnel}}
• Zcash, a cryptocurrency, uses BLAKE2b in the Equihash proof of work, and as a key derivation function
• NANO, a cryptocurrency, uses BLAKE2b in the proof of work, for hashing digital signatures and as a key derivation function{{cite web|url=https://docs.nano.org/integration-guides/work-generation/?h=+blake2b#work-equation|title=work|website=docs.nano.org}}{{cite web|url=https://docs.nano.org/whitepaper/english/?h=+blake2b#signing-algorithm|title=signatures|website=docs.nano.org}}{{cite web|url=https://docs.nano.org/integration-guides/the-basics/?h=+blake2b#seed|title=key derivation|website=docs.nano.org}}
• Polkadot, a multi-chain blockchain uses BLAKE2b as its hashing algorithm.
• Kadena (cryptocurrency), a scalable proof of work blockchain that uses Blake2s_256 as its hashing algorithm.
• PCI Vault, uses BLAKE2b as its hashing algorithm for the purpose of PCI compliant PCD tokenization.
• Ergo, a cryptocurrency, uses BLAKE2b256 as a subroutine of its hashing algorithm called Autolykos.{{cite web|url=https://ergoplatform.org/docs/ErgoPow.pdf|title=Autolykos: The Ergo Platform PoW Puzzle|website=ergoplatform.org}}
• Linux kernel, version 5.17 replaced SHA-1 with BLAKE2s for hashing the entropy pool in the random number generator.{{Cite web|url=https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.17-RNG|title=Linux 5.17 Random Number Generator Seeing Speed-Ups, Switching From SHA1 To BLAKE2s|website=www.phoronix.com}}
• Open Network for Digital Commerce, a Government of India initiative, uses BLAKE-512 to sign API requests.{{cite web|url=https://developers.becknprotocol.io/docs/infrastructure-layer-specification/authentication/subscriber-signing|title=Subscriber Signing - Beckn}}
• checksum, a Windows file hashing program has Blake2s as one of its algorithms{{Cite web|url=https://corz.org/windows/software/checksum/|title=checksum for Windows|website=corz.org}}

In addition to the reference implementation, the following cryptography libraries provide implementations of BLAKE2:

• Botan
• Bouncy Castle
• Crypto++
• Libgcrypt
• libsodium
• OpenSSL
• wolfSSL

{{Infobox encryption method

| name = BLAKE3

| image =

| caption =

| designers = Jack O'Connor, Samuel Neves, Jean-Philippe Aumasson, Zooko Wilcox-O'Hearn

| publish date = {{Start date and age|2020|01|09}}

| series =

| derived from = Bao, BLAKE2

| derived to =

| related to =

| certification =

| digest size = 256 bits, arbitrarily extensible

| structure = Merkle tree

| rounds = 7

| speed = 0.49 cpb on Cascade Lake-SP with AVX-512{{cite web|url=https://github.com/BLAKE3-team/BLAKE3-specs/raw/master/blake3.pdf|title=BLAKE3 – one function, fast everywhere|website=GitHub}}

| cryptanalysis =

}}

BLAKE3 is a cryptographic hash function based on Bao and BLAKE2, created by Jack O'Connor, Jean-Philippe Aumasson, Samuel Neves, and Zooko Wilcox-O'Hearn.{{cite web|url=https://github.com/oconnor663/bao/blob/ae247d2aff286dfe0a31d41b6afc02b263956091/docs/spec.md|title=An earlier version of Bao specified its own custom tree mode, which eventually grew into BLAKE3.|website=GitHub}} It was announced on January 9, 2020, at Real World Crypto.{{cite web|url=https://news.ycombinator.com/item?id=22023152|title=JPA and I announced BLAKE3 at the RWC lightning talks....|website=Hacker News}}

BLAKE3 is a single algorithm with many desirable features (parallelism, XOF, KDF, PRF and MAC), in contrast to BLAKE and BLAKE2, which are algorithm families with multiple variants. BLAKE3 has a binary tree structure, so it supports a practically unlimited degree of parallelism (both SIMD and multithreading) given long enough input. The official Rust and C implementations{{cite web|url=https://github.com/BLAKE3-team/BLAKE3|title=BLAKE3 official implementations|website=GitHub|access-date=12 January 2020}} are dual-licensed as public domain (CC0) and the Apache License.{{cite web|url=https://github.com/BLAKE3-team/BLAKE3/blob/master/LICENSE|title=This work is released into the public domain with CC0 1.0. Alternatively, it is licensed under the Apache License 2.0.|website=GitHub}}

BLAKE3 is designed to be as fast as possible. It is consistently a few times faster than BLAKE2. The BLAKE3 compression function is closely based on that of BLAKE2s, with the biggest difference being that the number of rounds is reduced from 10 to 7, a change based on the assumption that current cryptography is too conservative.{{cite conference |last1=Aumasson |first1=Jean-Philippe |title=Too Much Crypto |url=https://eprint.iacr.org/2019/1492.pdf |date=2020 |conference=Real World Crypto Symposium}} In addition to providing parallelism, the Merkle tree format also allows for verified streaming (on-the-fly verifying) and incremental updates.

• Total Commander supports BLAKE3 for file checksums.
• OpenZFS supports BLAKE3 from version 2.2{{Cite news |last=Larabel |first=Michael |date=13 October 2023 |title=OpenZFS 2.2 Released With Block Clning, Linux Container Support & Better Performanceo |url=https://www.phoronix.com/news/OpenZFS-2.2-Released |access-date=21 May 2025 |publisher=Phoronix}}

{{Reflist|30em}}

• [https://131002.net/blake/ The BLAKE web site]
• [https://blake2.net/ The BLAKE2 web site]
• [https://blake3.io/ The BLAKE3 web site]

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