Slide 11
Slide 11 text
RSA key
• Select p & q primes
• Calculate n = p*q
• Calculate φ = (p-1)*(q-1)
• Choose such e, relatively prime to φ
gcd(φ,e) == 1
• Compute such d, that
(ed-1) modφ=0
• Private key = (n,e)
• Public key = (n,d)
p=11 q=3
n = 11*3 = 33
φ = (11-1)*(3-1) = 20
e = 3
d=7
(ed-1) mod φ = 0
(3d-1) mod 20 = 0
3d-1 = 20n
d = (20n + 1)/3
d = (20*1+1)/3
d = 21/3
public key = (n, e) = (33, 3)
private key = (n, d) = (33, 7)