Skip to content

Instantly share code, notes, and snippets.

@ofaurax
Created March 30, 2016 15:04
Show Gist options
  • Select an option

  • Save ofaurax/6103869014c246f962ab30a513fb5b49 to your computer and use it in GitHub Desktop.

Select an option

Save ofaurax/6103869014c246f962ab30a513fb5b49 to your computer and use it in GitHub Desktop.
Modular Inverse for RSA in python
#!/usr/bin/env python3
p = 61
q = 53
n = p*q
phi = (p-1)*(q-1)
# Took from SO
def egcd(a, b):
if a == 0:
return (b, 0, 1)
g, y, x = egcd(b%a,a)
return (g, x - (b//a) * y, y)
def modinv(a, m):
g, x, y = egcd(a, m)
if g != 1:
raise Exception('No modular inverse')
return x%m
e = 17
d = modinv(e, phi)
print('P =', p)
print('Q =', q)
print('N =', n)
print('Phi =', phi)
print('E =', e)
print('D =', d)
print('(E*D)%Phi =', (e*d)%phi)
@mentocat
Copy link
Copy Markdown

Yo this took me forever to find, thank you so much this helped so much for my quantum computing class. You're a blessing hope that you have a good day

@WightmanC
Copy link
Copy Markdown

Struggled with the "d" this makes it so simple.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment