Affine module

class ciphers.Affine.Affine

Bases: flask_restful.Resource

A Simple Affine Cipher. y = mx+b

check_coprime(proposed_value, modolus)

Could just have a list of values but check if the user provided value is coprime with 26.

Parameters:

• proposed_value – The user provided value
• modolus – Constant value of 26.

Returns:

None if it is coprime otherwise an error message with coprime value.

decode(encoded, inverse, b)

Decode the selected character based off the intercept and coefficient. unencoded = inverse *(encoded -m)yt

encoded

The user’s message encoded

inverse

The inverse of the coefficient.

b

The intercept value.

Return

The decoded value of the given character.

egcd(a, b)

Extended Euclidean algorithm .. attribute:: a

The selected number

b

The selected modulus

Returns:The Greatest Common Denominator.

encode(user_input, m, b)

Encode the selected character based off the intercept and coefficient. .. attribute:: user_input

The user’s message

m

The coefficient of the picked character

b

The intercept value.

Return

The encoded value of the given character.

get()

Returns:The Encoded/Decoded User’s message in json format.

methods = {'GET'}

modinv(a, m)

https://stackoverflow.com/questions/4798654/modular-multiplicative-inverse-function-in-python This is to find the multiplicative inverse in order to check if the user provided value is coprime. It only exists when the gcd of a,m are 1.

a

The selected number

m

The selected modulus,26 is the default here.

Returns:None or the multiplicative inverse of the selected number.