Mono-alphabetic Substitution Cipher

Tags

cryptography

A substitution cipher in which each letter corresponds to one letter of the normal alphabet, and encrypting a string of letters with a key is the same as encrypting each individual letter independently.

\begin{align*} E_e (m) &= e(m_1) e(m_2) e(m_3) \ldots e(m_n) = c_1 c_2 c_3 \ldots c_n = c \
D_d ( c) &= d(c_1) d(c_2) d(c_3) \ldots d(c_n) = m \
\end{align*}