Detailed Explanation:

Answer: Option 1 — Digital security infrastructure

Public Key Infrastructure (PKI) is a comprehensive framework used specifically for digital security infrastructure in India. It enables secure electronic communication and transactions through digital certificates, certificate authorities, and cryptographic key pairs (public and private keys), ensuring authentication, confidentiality, integrity, and non-repudiation of digital data.

📝 Short Notes: Public Key Infrastructure (PKI)

• Definition: PKI is a set of roles, policies, hardware, software, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates and manage public-key encryption.
• Components: Includes Certificate Authority (CA), Registration Authority (RA), digital certificates, certificate repositories, and certificate revocation lists (CRL).
• Function: Uses asymmetric cryptography with a pair of keys - public key (shared openly) and private key (kept secret) for encryption and digital signatures.
• Applications in India: Used in e-governance initiatives, digital signatures, secure email, online banking, e-commerce, and Aadhaar-based authentication.
• Controller of Certifying Authorities (CCA): Under the IT Act 2000, CCA is the authority to license and regulate Certifying Authorities in India.
• Benefits: Ensures data confidentiality, integrity, authentication, and non-repudiation in digital communications and transactions.