Digest.BLAKE256(3) OCaml library Digest.BLAKE256(3)

# [NAME](#NAME)

Digest.BLAKE256 - BLAKE256 is the BLAKE2b hash function producing 256-bit (32-byte) digests.

# [Module](#Module)

Module Digest.BLAKE256

# [Documentation](#Documentation)

Module **BLAKE256**  
: **S**

**BLAKE256** is the BLAKE2b hash function producing 256-bit (32-byte) digests. It is cryptographically secure, and the digests are large enough to thwart brute-force attacks.

**Since** 5.2

*type t* = **string**

The type of digests.

*val hash\_length* : **int**

The length of digests, in bytes.

*val compare* : **t -> t -> int**

Compare two digests, with the same specification as **compare** .

*val equal* : **t -> t -> bool**

Test two digests for equality.

*val string* : **string -> t**

Return the digest of the given string.

*val bytes* : **bytes -> t**

Return the digest of the given byte sequence.

*val substring* : **string -> int -> int -> t**

**substring s ofs len** returns the digest of the substring of **s** starting at index **ofs** and containing **len** characters.

*val subbytes* : **bytes -> int -> int -> t**

**subbytes s ofs len** returns the digest of the subsequence of **s** starting at index **ofs** and containing **len** bytes.

*val channel* : **in\_channel -> int -> t**

Read characters from the channel and return their digest. See **Digest.channel** for the full specification.

*val file* : **string -> t**

Return the digest of the file whose name is given.

*val output* : **out\_channel -> t -> unit**

Write a digest on the given output channel.

*val input* : **in\_channel -> t**

Read a digest from the given input channel.

*val to\_hex* : **t -> string**

Return the printable hexadecimal representation of the given digest.

**Raises Invalid\_argument** if the length of the argument is not **hash\_length** ,

*val of\_hex* : **string -> t**

Convert a hexadecimal representation back into the corresponding digest.

**Raises Invalid\_argument** if the length of the argument is not **2 * hash\_length** , or if the arguments contains non-hexadecimal characters.

2026-10-23 OCamldoc

---

Document: Digest.BLAKE256(3o) from ocaml 5.5.2-r0 (Chainguard OS)
Source: https://github.com/ocaml/ocaml