Show activity on this post. Bitcoin uses ECDSA, and the reason **the signature is different for the same message** and key is the random nonce, which is generated each time a signature is created.

## What signatures does Bitcoin use?

Currently, Bitcoin uses the **Elliptic Curve Digital Signature Algorithm (ECDSA)**. With the Taproot upgrade, Bitcoin will integrate Schnorr, a second type of signature scheme with several advantages.

## Are Ecdsa signature deterministic?

**Deterministic elliptic-curve signatures such as deterministic ECDSA and EdDSA have gained popularity over randomized ECDSA as their security do not depend on a source of high-quality randomness**.

## How long is Ecdsa signature?

ECDSA signatures are **2 times longer than the signer’s private key for the curve used during the signing process**. For example, for 256-bit elliptic curves (like secp256k1 ) the ECDSA signature is 512 bits (64 bytes) and for 521-bit curves (like secp521r1 ) the signature is 1042 bits.

## What is r s v in signature?

ECDSA signatures consist of two numbers (integers): r and s . Ethereum also uses an additional v (**recovery identifier) variable**. The signature can be notated as {r, s, v} . To create a signature you need the message to sign and the private key ( dₐ ) to sign it with.

## How long is an ethereum signature?

Recovering the message signer in the smart contract

ECDSA signatures in Ethereum consist of three parameters: v , r and s . The signature is always **65-bytes** in length.