RSA is best described as?

RSA is best described as?

• A. A symmetric algorithm
• B. A block cipher
• C. A public-key cryptosystem
• D. A hashing function

Answer: (C)

RSA is a public-key cryptosystem. This means it uses a pair of keys: a publicly shared key used to encrypt messages (or verify signatures) and a private key kept secret used to decrypt messages (or create signatures). The security relies on the difficulty of factoring large numbers that are the product of two primes. In operation, someone can encrypt with the public key, and only the private key holder can decrypt it, enabling secure communication or authentication. This is different from symmetric algorithms, which rely on a single shared secret for both encryption and decryption. It’s also not a block cipher, which processes data in fixed-size blocks, and not a hashing function, which produces a fixed digest and is not reversible. RSA is widely used for secure key exchange, digital signatures, and certificate-based authentication.

RSA is a public-key cryptosystem. This means it uses a pair of keys: a publicly shared key used to encrypt messages (or verify signatures) and a private key kept secret used to decrypt messages (or create signatures). The security relies on the difficulty of factoring large numbers that are the product of two primes. In operation, someone can encrypt with the public key, and only the private key holder can decrypt it, enabling secure communication or authentication. This is different from symmetric algorithms, which rely on a single shared secret for both encryption and decryption. It’s also not a block cipher, which processes data in fixed-size blocks, and not a hashing function, which produces a fixed digest and is not reversible. RSA is widely used for secure key exchange, digital signatures, and certificate-based authentication.