Some Math behind RSA Algorithm -I

• RSA stands for inventors: Rivest Shamir and Adleman

• Take a number n = p * q where p and q are primes

• Choose a “suitable” number e

• Public key is <e,n> and basic encryption algorithm takes message m to be encrypted and forms

  • c = me mod(n)

• Decryption involves private key d which is found so that

  • d * e = 1 mod((p-1)(q-1))

• Then m = cd mod(n)

• As factorization is computationally infeasible (for n of 512 bits in length or more), this encryption cannot be broken.

Previous slide

Next slide

Back to first slide

View graphic version