Class RSAAlgorithm

java.lang.Object

org.episteme.core.mathematics.cryptography.RSAAlgorithm

public class RSAAlgorithm
extends Object

The RSA (Rivest–Shamir–Adleman) encryption algorithm.

RSA is a public-key cryptosystem that is widely used for secure data transmission. It is based on the practical difficulty of the factorization of the product of two large prime numbers, the "factoring problem".

References

• Wikipedia: RSA (cryptosystem)
• Rivest, R. L., Shamir, A., invalid input: '&' Adleman, L. (1978). "A Method for Obtaining Digital Signatures and Public-Key Cryptosystems". Communications of the ACM, 21(2), 120–126.
• Menezes, A. J., van Oorschot, P. C., invalid input: '&' Vanstone, S. A. (1996). Handbook of Applied Cryptography. CRC Press.

Since:

1.0

Author:

Silvere Martin-Michiellot, Gemini AI (Google DeepMind)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	RSAAlgorithm.KeyPair
static class	RSAAlgorithm.PrivateKey
static class	RSAAlgorithm.PublicKey

Constructor Summary

Constructors

Constructor	Description
RSAAlgorithm()

Method Summary

Modifier and Type	Method	Description
static BigInteger	decrypt(BigInteger ciphertext, RSAAlgorithm.PrivateKey privateKey)	Decrypts ciphertext using private key: m = c^d mod n
static BigInteger	encrypt(BigInteger message, RSAAlgorithm.PublicKey publicKey)	Encrypts message using public key: c = m^e mod n
static RSAAlgorithm.KeyPair	generateKeyPair(int bitLength)	Generates RSA key pair.
static BigInteger	sign(BigInteger message, RSAAlgorithm.PrivateKey privateKey)	Signs message using private key.
static boolean	verify(BigInteger message, BigInteger signature, RSAAlgorithm.PublicKey publicKey)	Verifies signature using public key.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RSAAlgorithm

public RSAAlgorithm()

Method Details

generateKeyPair

public static RSAAlgorithm.KeyPair generateKeyPair(int bitLength)

Generates RSA key pair.

Parameters:

bitLength - key size in bits (e.g., 2048, 4096)

Returns:

public and private keys

encrypt

public static BigInteger encrypt(BigInteger message,
 RSAAlgorithm.PublicKey publicKey)

Encrypts message using public key: c = m^e mod n

decrypt

public static BigInteger decrypt(BigInteger ciphertext,
 RSAAlgorithm.PrivateKey privateKey)

Decrypts ciphertext using private key: m = c^d mod n

sign

public static BigInteger sign(BigInteger message,
 RSAAlgorithm.PrivateKey privateKey)

Signs message using private key.

verify

public static boolean verify(BigInteger message,
 BigInteger signature,
 RSAAlgorithm.PublicKey publicKey)

Verifies signature using public key.