Subject: Science & Technology

A digital signature is a mathematical technique used to validate the authenticity and integrity of digital messages, documents, or software. In today's digital age, where cyber threats are increasing exponentially, digital signatures have become crucial for secure electronic transactions and communications.

Components of Digital Signature

• It consists of three key algorithms - key generation, signing algorithm, and signature verifying algorithm.
• Uses asymmetric cryptography with public and private key pairs for enhanced security.
• Incorporates hash functions to create a unique fingerprint of the digital document.

Authentication Process

• Message Encryption: The sender encrypts the document using their private key.
• Hash Value Generation: Creates a unique mathematical value for the document content.
• Verification Process: Recipient uses sender's public key to decrypt and verify authenticity.
• Timestamp Validation: Ensures the signature's time validity through trusted timestamp authorities.

Salient Built-in Features

• Non-repudiation: Sender cannot deny sending the signed document (legally binding under IT Act, 2000).
• Integrity Check: Any modification to the document after signing invalidates the signature.
• Time-stamping: Provides proof of when the document was signed.
• Tamper-evident: Automatically detects unauthorized changes to documents.
• Multi-factor Authentication: Additional security layers through OTP or biometric verification.

Security Measures

• PKI Infrastructure: Relies on trusted Certificate Authorities (CAs) for key management.
• Digital Certificates: Contains owner's public key and identity information.
• Encryption Standards: Uses advanced algorithms like SHA-256 and RSA for security.

In an era where cyber fraud cases have increased fourfold in FY2024, with losses of $20 million, digital signatures provide a secure foundation for electronic transactions. The technology's integration with initiatives like Digital India and legal recognition through the IT Act makes it an essential tool for secure digital transformation.