gistfile1.txt

\documentclass{article}
\usepackage{amsmath}
\usepackage{algorithm}
\usepackage{algpseudocode}

\begin{document}

\noindent
\begin{minipage}{0.45\linewidth}
    \raggedright
    \textbf{\(\mathcal{S_E}_K(M)\)} \\[5pt]
    \begin{algorithmic}[1]
        \State \textbf{Break} \( M \) into \( n \)-bit blocks:
        \State \( M_1 \parallel \dots \parallel M_p \)
        \State \( IV \gets \${0,1}^n \)
        \State \( C_0 \gets IV \)
        \State \( C_1 \gets E(K, IV) \)
        \For{\( i = 1 \) to \( p \)}
            \State \( C_{i+1} \gets E(K, C_i \oplus M_i) \)
        \EndFor
        \State \textbf{Return} \( C_0 \parallel C_1 \parallel \dots \parallel C_{p+1} \)
    \end{algorithmic}
\end{minipage}
\hfill\vline\hfill
\begin{minipage}{0.45\linewidth}
    \raggedright
    \textbf{\(\mathcal{S_D}_K(C)\)} \\[5pt]
    \begin{algorithmic}[1]
        \State \textbf{Break} \( C \) into \( n \)-bit blocks:
        \State \( C_0 \parallel C_1 \parallel \dots \parallel C_{p+1} \)
        \For{\( i = 1 \) to \( p \)}
            \State \( M_i \gets E^{-1}(K, C_{i+1}) \oplus C_i \)
        \EndFor
        \State \( M \gets M_1 \parallel \dots \parallel M_p \)
        \State \( IV \gets E^{-1}(K, C_1) \)
        \If{\( IV \neq C_0 \)}
            \State \textbf{Return} \( \perp \)
        \Else
            \State \textbf{Return} \( M \)
        \EndIf
    \end{algorithmic}
\end{minipage}

\end{document}