Struct secp256k1::ellswift::ElligatorSwift

pub struct ElligatorSwift(/* private fields */);

ElligatorSwift is an encoding of a uniformly chosen point on the curve as a 64-byte array that is indistinguishable from a uniformly random array. This object holds two field elements u and t, which are the inputs to the ElligatorSwift encoding function.

Implementations

impl ElligatorSwift

pub fn new(secret_key: SecretKey, rand: [u8; 32]) -> ElligatorSwift

Create a new ElligatorSwift object from a 64-byte array.

pub fn from_array(ellswift: [u8; 64]) -> ElligatorSwift

Creates an ElligatorSwift object from a 64-byte array.

pub fn to_array(&self) -> [u8; 64]

Returns the 64-byte array representation of this ElligatorSwift object.

pub fn from_seckey<C: Verification>( secp: &Secp256k1<C>, sk: SecretKey, aux_rand: Option<[u8; 32]>, ) -> ElligatorSwift

Creates the Elligator Swift encoding from a secret key, using some aux_rand if defined. This method is preferred instead of just decoding, because the private key offers extra entropy.

Example

    use secp256k1::{ellswift::ElligatorSwift, PublicKey, Secp256k1, SecretKey};
    let secp = Secp256k1::new();
    let sk = SecretKey::from_slice(&[1; 32]).unwrap();
    let es = ElligatorSwift::from_seckey(&secp, sk, None);

pub fn from_pubkey(pk: PublicKey) -> ElligatorSwift

Computes the ElligatorSwift encoding for a valid public key

Example

    use secp256k1::{ellswift::ElligatorSwift, PublicKey, Secp256k1, SecretKey};
    let secp = Secp256k1::new();
    let sk = SecretKey::from_slice(&[1; 32]).unwrap();
    let pk = PublicKey::from_secret_key(&secp, &sk);
    let es = ElligatorSwift::from_pubkey(pk);

pub fn shared_secret( ellswift_a: ElligatorSwift, ellswift_b: ElligatorSwift, secret_key: SecretKey, party: ElligatorSwiftParty, data: Option<&[u8]>, ) -> ElligatorSwiftSharedSecret

Computes a shared secret only known by Alice and Bob. This is obtained by computing the x-only Elliptic Curve Diffie-Hellman (ECDH) shared secret between Alice and Bob.

Example

    use secp256k1::{
        ellswift::{ElligatorSwift, ElligatorSwiftParty},
        PublicKey, SecretKey, XOnlyPublicKey, Secp256k1,
    };
    use core::str::FromStr;

    let secp = Secp256k1::new();

    let alice_sk = SecretKey::from_str("e714e76bdd67ad9f495683c37934148f4efc25ce3f01652c8a906498339e1f3a").unwrap();
    let bob_sk = SecretKey::from_str("b6c4b0e2f8c4359caf356a618cd1649d18790a1d67f7c2d1e4760e04c785db4f").unwrap();

    let alice_es = ElligatorSwift::from_seckey(&secp, alice_sk, None);
    let bob_es = ElligatorSwift::from_seckey(&secp, bob_sk, None);

    let alice_shared_secret = ElligatorSwift::shared_secret(alice_es, bob_es, alice_sk, ElligatorSwiftParty::A, None);
    let bob_shared_secret = ElligatorSwift::shared_secret(alice_es, bob_es, bob_sk, ElligatorSwiftParty::B, None);

    assert_eq!(alice_shared_secret, bob_shared_secret);

pub fn shared_secret_with_hasher<F>( ellswift_a: ElligatorSwift, ellswift_b: ElligatorSwift, secret_key: SecretKey, party: ElligatorSwiftParty, hash_function: F, ) -> ElligatorSwiftSharedSecret

where F: FnMut([u8; 32], [u8; 64], [u8; 64]) -> ElligatorSwiftSharedSecret,

Computes a shared secret, just like shared_secret, but with a custom hash function for computing the shared secret. For compatibility with other libraries, you should use shared_secret instead, which is already compatible with BIP324. The hash function takes three arguments: the shared point, and the ElligatorSwift encodings of the two parties and returns a 32-byte shared secret.

Trait Implementations

impl CPtr for ElligatorSwift

type Target = u8

fn as_mut_c_ptr(&mut self) -> *mut Self::Target

fn as_c_ptr(&self) -> *const Self::Target

impl Clone for ElligatorSwift

fn clone(&self) -> ElligatorSwift

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ElligatorSwift

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

Formats the value using the given formatter.

impl Display for ElligatorSwift

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

Formats the value using the given formatter.

impl FromStr for ElligatorSwift

fn from_str(hex: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

type Err = Error

The associated error which can be returned from parsing.

impl Hash for ElligatorSwift

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl LowerHex for ElligatorSwift

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

Formats the value using the given formatter.

impl Ord for ElligatorSwift

fn cmp(&self, other: &ElligatorSwift) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for ElligatorSwift

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd for ElligatorSwift

fn partial_cmp(&self, other: &ElligatorSwift) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for ElligatorSwift

impl Eq for ElligatorSwift

impl StructuralPartialEq for ElligatorSwift