What are three broad categories of applications of public-key cryptosystems explain?

Answer 1

Public-key cryptosystems can be broadly categorized into three applications: encryption, digital signatures, and key exchange.

1. Encryption: They enable secure communication by allowing users to encrypt messages with a recipient's public key, ensuring that only the recipient can decrypt it with their private key.

2. Digital Signatures: Public-key systems facilitate the creation of digital signatures, which verify the authenticity and integrity of a message or document, ensuring that it has not been altered and confirming the identity of the sender.

3. Key Exchange: They support secure key exchange mechanisms, allowing two parties to securely establish a shared secret key over an insecure channel, often utilizing algorithms like Diffie-Hellman.