RSA Algorithm
What is RSA Algorithm?
RSA AlgorithmA public-key algorithm by Rivest, Shamir and Adleman (1977) whose security rests on the difficulty of factoring the product of two large prime numbers.
RSA generates a key pair by choosing two large primes p and q, computing the modulus n = p·q and the Euler totient φ(n), then selecting a public exponent e (commonly 65537) and computing the private exponent d as the inverse of e modulo φ(n). Encryption is m^e mod n; decryption is c^d mod n. RSA supports both encryption (via padding schemes like OAEP) and digital signatures (RSA-PSS). Its security relies on the assumed hardness of integer factorization; for 128-bit equivalent security NIST currently requires at least 3072-bit RSA keys. RSA is slower than elliptic-curve alternatives and will be vulnerable to large-scale quantum computers, so post-quantum schemes such as ML-KEM and ML-DSA are being standardised to replace it for new deployments.
● Examples
- 01
Most TLS server certificates issued before 2020 use RSA-2048 or RSA-3072 keys.
- 02
GPG email signatures often use 4096-bit RSA key pairs.
● Frequently asked questions
What is RSA Algorithm?
A public-key algorithm by Rivest, Shamir and Adleman (1977) whose security rests on the difficulty of factoring the product of two large prime numbers. It belongs to the Cryptography category of cybersecurity.
What does RSA Algorithm mean?
A public-key algorithm by Rivest, Shamir and Adleman (1977) whose security rests on the difficulty of factoring the product of two large prime numbers.
How do you defend against RSA Algorithm?
Defences for RSA Algorithm typically combine technical controls and operational practices, as detailed in the full definition above.
What are other names for RSA Algorithm?
Common alternative names include: RSA, Rivest–Shamir–Adleman.