Suppose that the 26 symbol alphabet $A,...,Z$ is used for all plaintext and ciphertext messages in an RSA cryptosystem. Suppose also that plaintext message units are length $2$ and ciphertext units are length $3$.
A user has a public key $(943,3)$
i) Encrypt for transmission to A the message
MATHEMATICAL
Okay, so $(943,3)$ = (n, e). $k=2, l=3$.
$943=23*41$
MATHEMATICAL = $12, 0, 19, 7, 4, 12, 0, 19, 8, 2, 0, 11$
What are the next steps? How do I finish this? The example is my notes is fairly complicated and uses Maple for one of the calculations which is confusing me as we have to do this in a class test? .. Without access to any computer programs...
If someone could explain this to me, that would be great! :)
RSA encryption works as follows, you have a modulus $n$ (in this case $943$) and an encryption exponent $e$ (in this case $3$). To encrypt a plaintext message $m$ you compute $c=m^e\bmod{n}$. So, if $m=12$, we get $12^3\equiv 785 \bmod{943}$.