What is a digital signature

A digital signature is a cryptographic technique used to verify the authenticity and integrity of digital messages or documents. Key aspects include:

1. **Authentication:** Confirms the identity of the sender by using their private key to create the signature.

2. **Integrity:** Ensures that the message or document has not been altered since it was signed. Any modification after signing will invalidate the signature.

3. **Non-repudiation:** Provides proof that the sender cannot deny having signed the document, as the digital signature is uniquely associated with their private key.

4. **Verification:** Recipients use the sender's public key to verify the authenticity and integrity of the digital signature.

Digital signatures are widely used in secure communications, electronic transactions, and document verification.