Struct bitcoin::key::secp256k1::PublicKey

pub struct PublicKey(_);

Expand description

A Secp256k1 public key, used for verification of signatures.

Serde support

Implements de/serialization with the serde feature enabled. We treat the byte value as a tuple of 33 u8s for non-human-readable formats. This representation is optimal for for some formats (e.g. bincode) however other formats may be less optimal (e.g. cbor).

Examples

Basic usage:

use secp256k1::{SecretKey, Secp256k1, PublicKey};

let secp = Secp256k1::new();
let secret_key = SecretKey::from_slice(&[0xcd; 32]).expect("32 bytes, within curve order");
let public_key = PublicKey::from_secret_key(&secp, &secret_key);

Implementations§

§

impl PublicKey

pub fn cmp_fast_unstable(&self, other: &PublicKey) -> Ordering

Like cmp::Cmp but faster and with no guarantees across library versions.

The Cmp implementation for FFI types is stable but slow because it first serializes self and other before comparing them. This function provides a faster comparison if you know that your types come from the same library version.

pub fn eq_fast_unstable(&self, other: &PublicKey) -> bool

Like cmp::Eq but faster and with no guarantees across library versions.

The Eq implementation for FFI types is stable but slow because it first serializes self and other before comparing them. This function provides a faster equality check if you know that your types come from the same library version.

§

impl PublicKey

pub fn as_ptr(&self) -> *const PublicKey

👎Deprecated since 0.25.0: Use Self::as_c_ptr if you need to access the FFI layer

Obtains a raw const pointer suitable for use with FFI functions.

pub fn as_mut_ptr(&mut self) -> *mut PublicKey

👎Deprecated since 0.25.0: Use Self::as_mut_c_ptr if you need to access the FFI layer

Obtains a raw mutable pointer suitable for use with FFI functions.

pub fn from_secret_key<C>(secp: &Secp256k1<C>, sk: &SecretKey) -> PublicKeywhere C: Signing,

Creates a new public key from a SecretKey.

Examples

use secp256k1::{rand, Secp256k1, SecretKey, PublicKey};

let secp = Secp256k1::new();
let secret_key = SecretKey::new(&mut rand::thread_rng());
let public_key = PublicKey::from_secret_key(&secp, &secret_key);

pub fn from_slice(data: &[u8]) -> Result<PublicKey, Error>

Creates a public key directly from a slice.

pub fn from_keypair(keypair: &KeyPair) -> PublicKey

Creates a new compressed public key using data from BIP-340 KeyPair.

Examples

use secp256k1::{rand, Secp256k1, PublicKey, KeyPair};

let secp = Secp256k1::new();
let key_pair = KeyPair::new(&secp, &mut rand::thread_rng());
let public_key = PublicKey::from_keypair(&key_pair);

pub fn from_x_only_public_key(pk: XOnlyPublicKey, parity: Parity) -> PublicKey

Creates a PublicKey using the key material from pk combined with the parity.

pub fn serialize(&self) -> [u8; 33]

Serializes the key as a byte-encoded pair of values. In compressed form the y-coordinate is represented by only a single bit, as x determines it up to one bit.

pub fn serialize_uncompressed(&self) -> [u8; 65]

Serializes the key as a byte-encoded pair of values, in uncompressed form.

pub fn negate<C>(self, secp: &Secp256k1<C>) -> PublicKeywhere C: Verification,

Negates the public key.

pub fn add_exp_tweak<C>( self, secp: &Secp256k1<C>, tweak: &Scalar ) -> Result<PublicKey, Error>where C: Verification,

Tweaks a PublicKey by adding tweak * G modulo the curve order.

Errors

Returns an error if the resulting key would be invalid.

pub fn mul_tweak<C>( self, secp: &Secp256k1<C>, other: &Scalar ) -> Result<PublicKey, Error>where C: Verification,

Tweaks a PublicKey by multiplying by tweak modulo the curve order.

Errors

Returns an error if the resulting key would be invalid.

pub fn combine(&self, other: &PublicKey) -> Result<PublicKey, Error>

Adds a second key to this one, returning the sum.

Errors

If the result would be the point at infinity, i.e. adding this point to its own negation.

Examples

use secp256k1::{rand, Secp256k1};

let secp = Secp256k1::new();
let mut rng = rand::thread_rng();
let (_, pk1) = secp.generate_keypair(&mut rng);
let (_, pk2) = secp.generate_keypair(&mut rng);
let sum = pk1.combine(&pk2).expect("It's improbable to fail for 2 random public keys");

pub fn combine_keys(keys: &[&PublicKey]) -> Result<PublicKey, Error>

Adds the keys in the provided slice together, returning the sum.

Errors

Errors under any of the following conditions:

The result would be the point at infinity, i.e. adding a point to its own negation.
The provided slice is empty.
The number of elements in the provided slice is greater than i32::MAX.

Examples

use secp256k1::{rand, Secp256k1, PublicKey};

let secp = Secp256k1::new();
let mut rng = rand::thread_rng();
let (_, pk1) = secp.generate_keypair(&mut rng);
let (_, pk2) = secp.generate_keypair(&mut rng);
let (_, pk3) = secp.generate_keypair(&mut rng);
let sum = PublicKey::combine_keys(&[&pk1, &pk2, &pk3]).expect("It's improbable to fail for 3 random public keys");

pub fn x_only_public_key(&self) -> (XOnlyPublicKey, Parity)

Returns the XOnlyPublicKey (and it’s Parity) for this PublicKey.

Trait Implementations§

§

impl CPtr for PublicKey

This trait enables interaction with the FFI layer and even though it is part of the public API normal users should never need to directly interact with FFI types.

§