ECDSA Digital Signature Demonstration

Main Purpose and Learning Objectives

This page demonstrates how the Elliptic Curve Digital Signature Algorithm (ECDSA) works in a simple, interactive way. The main objectives are to help users understand the process of:

• Generating a private and public key pair.
• Signing a message to create a digital signature.
• Verifying a signature to ensure authenticity and integrity.

Theory: Why Digital Signatures Matter

ECDSA is a widely used cryptographic technique in secure communications, such as blockchain, secure emails, and financial transactions. It ensures:

• Authenticity: Only the holder of the private key could have signed the message.
• Integrity: The message has not been altered since it was signed.
• Non-repudiation: The signer cannot later deny signing the message.

ECDSA is based on the difficulty of the Elliptic Curve Discrete Logarithm Problem (ECDLP), making it highly secure with smaller key sizes compared to traditional RSA.

Setup and Parameters

• Curve: secp256k1 (same as Bitcoin)
• Hash Function: SHA-256
• Private Key: A random 256-bit number (hexadecimal).
• Public Key: A point (X, Y) on the elliptic curve derived from the private key.
• Signature: A proof that a specific private key holder signed the message.

User Guide

1. Upon loading the page, a private key is automatically generated and displayed.
2. Enter a message you want to sign and click "Sign Message".
3. The system generates a digital signature and shows the corresponding public key.
4. To verify, enter the same message, public key, and signature, then click "Verify Signature".
5. If everything matches correctly, the verification will succeed!