# What is affine cipher in cryptography?

## What is affine cipher in cryptography?

Affine Ciphers. An affine cipher, (like a shift cipher), is an example of a substitution cipher: In encryption using a substitution cipher, each time a given letter occurs in the plaintext, it always is replaced by the same ciphertext letter.

What is the Keyspace of affine cipher?

The 312 affine ciphers include, as special cases, the 26 Caesar ciphers (the affine ciphers with m = 1; C = p + b) and the multiplicative ciphers (the affine ciphers with b = 0, C = mp). That’s still a small keyspace. Here is an example of an affine cipher with additive key 5 and multiplicative key 7.

What is A and B in affine cipher?

The affine cipher applies multiplication and addition to each character using the function: y = (ax + b) MOD m. where x is the numerical value of the letter in the plaintext, m is the number of letters in the plaintext alphabet, a and b are the secret numbers, and y is the result of transformation.

### What is affine cipher transformation?

The affine cipher is a type of monoalphabetic substitution cipher, where each letter in an alphabet is mapped to its numeric equivalent, encrypted using a simple mathematical function, and converted back to a letter. Each letter is enciphered with the function (ax + b) mod 26, where b is the magnitude of the shift.

How many keys are there in affine cipher?

Since, for the standard alphabet, there are 12 numbers less than 26 which are coprime to 26, and for each of these there are 26 possibilities for the value of b, we have a total of 12 x 26 = 312 possible keys for the Affine Cipher.

What is an affine subspace?

An affine subspace (also called, in some contexts, a linear variety, a flat, or, over the real numbers, a linear manifold) B of an affine space A is a subset of A such that, given a point , the set of vectors is a linear subspace of .

## What is meant by affine function?

An affine function is a function composed of a linear function + a constant and its graph is a straight line. The general equation for an affine function in 1D is: y = Ax + c. An affine function demonstrates an affine transformation which is equivalent to a linear transformation followed by a translation.