Struct Signature 

pub struct Signature {
    pub rx: BaseField,
    pub s: ScalarField,
}

A Schnorr signature for the Mina protocol.

This structure represents a cryptographic signature that consists of two components:

• rx: The x-coordinate of the commitment point R, represented as a base field element
• s: The signature scalar, computed as s = k + r * private_key where k is a random nonce

The signature follows the standard Schnorr signature scheme adapted for Mina’s elliptic curve choice (Pallas curve). This ensures compatibility with the Mina blockchain’s verification requirements.

Security Properties

• Unforgeability: Cannot be forged without knowledge of the private key
• Non-malleability: Signature cannot be modified to create a valid signature for a different message
• Deterministic: Given the same message and private key, produces the same signature (when using deterministic nonce generation)

Field Element Encoding

• rx is encoded as a base field element (typically Fp for Pallas curve)
• s is encoded as a scalar field element (typically Fq for Pallas curve)

Both components are essential for signature verification and must be preserved with full precision during serialization and transmission.

Fields

rx: BaseField

The x-coordinate of the commitment point R from the Schnorr signature.

This value is derived from the random nonce used during signing and represents the x-coordinate of the point R = k * G, where k is the nonce and G is the generator point of the elliptic curve.

The rx component is crucial for signature verification as it’s used to reconstruct the commitment point during the verification process.

s: ScalarField

The signature scalar component.

This scalar is computed as s = k + r * private_key (mod n), where:

• k is the random nonce used during signing
• r is the challenge derived from the commitment point and message
• private_key is the signer’s secret key
• n is the order of the scalar field

The scalar s proves knowledge of the private key without revealing it, making it the core component that provides the signature’s authenticity.

Implementations

impl Signature

pub const fn new(rx: BaseField, s: ScalarField) -> Self

Creates a new signature from the given field elements.

This constructor builds a signature from its two core components: the commitment point’s x-coordinate and the signature scalar.

Arguments

• rx - The x-coordinate of the commitment point R, as a base field element
• s - The signature scalar, as a scalar field element

Returns

A new Signature instance containing the provided components.

Examples

use mina_signer::{Signature, BaseField, ScalarField};

let rx = BaseField::from(123u64);
let s = ScalarField::from(456u64);
let signature = Signature::new(rx, s);

assert_eq!(signature.rx, rx);
assert_eq!(signature.s, s);

Security Note

This constructor does not validate that the provided components form a valid signature for any particular message or public key. It simply creates the data structure. Signature validation must be performed separately using appropriate verification functions.

pub fn dummy() -> Self

Create a dummy signature, whose components are both equal to one. Use it with caution.

Trait Implementations

impl Clone for Signature

fn clone(&self) -> Signature

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Signature

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Signature

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the signature as a hexadecimal string.

Returns the signature as concatenated hex-encoded bytes in big-endian order: rx || s.

impl Eq for Signature

impl PartialEq for Signature

fn eq(&self, other: &Signature) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Signature