category

ed25519

Ed25519 (RFC 8032) public-key signature implementation. Requires exact, unbounded integer arithmetic for arithmetic modulo the 255-bit field prime and modulo the group order.

Availability:
logtalk_load(crypto(loader))
Author: Paulo Moura
Version: 1:0:0
Date: 2026-08-02
Compilation flags:
static
Complements:
crypto
Uses:
list
sha512
type
Remarks:
(none)
Inherited public predicates:
(none)

Public predicates

ed25519_keypair/2

Generates a fresh random 32-byte Seed and derives the corresponding 32-byte PublicKey. The seed is the value to keep secret and to pass to ed25519_sign/3; it is also sometimes called the “secret key”. Available only on backends with unbounded integer arithmetic.

Compilation flags:
static
Template:
ed25519_keypair(Seed,PublicKey)
Mode and number of proofs:
ed25519_keypair(-list(byte),-list(byte)) - one

ed25519_public_key/2

Derives the 32-byte PublicKey corresponding to a 32-byte Seed. Available only on backends with unbounded integer arithmetic.

Compilation flags:
static
Template:
ed25519_public_key(Seed,PublicKey)
Mode and number of proofs:
ed25519_public_key(+list(byte),-list(byte)) - one_or_error
Exceptions:
Seed is a partial list or a list with an element which is a variable:
instantiation_error
Seed is neither a variable nor a list of 32 bytes:
type_error(list(byte,32),Seed)
Seed contains a non-integer byte:
type_error(integer,Byte)
Seed contains an integer outside the byte range:
domain_error(byte,Byte)

ed25519_sign/3

Computes the 64-byte Ed25519 Signature of Message using Seed. Not constant-time; see the module-level note on this section. Available only on backends with unbounded integer arithmetic.

Compilation flags:
static
Template:
ed25519_sign(Seed,Message,Signature)
Mode and number of proofs:
ed25519_sign(+list(byte),+list(byte),-list(byte)) - one_or_error
Exceptions:
Seed is a partial list or a list with an element which is a variable:
instantiation_error
Seed is neither a variable nor a list of 32 bytes:
type_error(list(byte,32),Seed)
Seed contains a non-integer byte:
type_error(integer,Byte)
Seed contains an integer outside the byte range:
domain_error(byte,Byte)
Message is a partial list or a list with an element which is a variable:
instantiation_error
Message is neither a variable nor a list of bytes:
type_error(list(byte),Message)
Message contains a non-integer byte:
type_error(integer,Byte)
Message contains an integer outside the byte range:
domain_error(byte,Byte)

ed25519_verify/3

Succeeds if Signature is a valid Ed25519 signature of Message under PublicKey, and fails otherwise (invalid signature, non-canonical S, non-canonical or small-order PublicKey or R component, or malformed input lengths); see the module-level note on this section for the exact verification policy. Available only on backends with unbounded integer arithmetic.

Compilation flags:
static
Template:
ed25519_verify(PublicKey,Message,Signature)
Mode and number of proofs:
ed25519_verify(+list(byte),+list(byte),+list(byte)) - zero_or_one

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

(no local declarations; see entity ancestors if any)

Operators

(none)