\documentclass[border={30pt 0pt 0pt 30pt}]{standalone}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{automata, positioning, arrows, shapes.geometric}

\usepackage{environ}

\usepackage[margin=2cm]{geometry}
\renewcommand{\baselinestretch}{1.15}
\setlength{\parskip}{6pt}

\begin{document}

\begin{tikzpicture}[node distance=2cm]
	\node(sk0)[draw]{$SK_0$};
	\node(sk1)[draw, right of=sk0]{$SK_1$};
	\node(skD)[right of=sk1]{$...$};
	\node(skT)[draw, right of=skD]{$SK_t$};
	
	\node(sEpID)[draw, below of=sk1]{$S\_EpID$};
	\node(sEpIDD)[below of=skT, yshift=0.5cm]{$...$};
	
	\node(epID1)[draw, below of=sEpID]{$EpID_1$};
	\node(epID0)[draw, left of=epID1]{$EpID_0$};
	\node(epIDD)[right of=epID1]{$...$};
	\node(epIDN)[draw, right of=epIDD]{$EpID_n$};
	
	\draw[->] (sk0) -- (sk1);
	\draw[-]  (sk1) -- (skD);
	\draw[->] (skD) -- (skT);
	
	\draw[->] (sk1) -- (sEpID);
	\draw[->] (skT) -- (sEpIDD);
	
	\draw[->] (sEpID) -| (epID0);
	\draw[->] (sEpID) -- (epID1);
	\draw[->] (sEpID) -| (epIDN);
\end{tikzpicture}

\end{document}