From 4a5d278f55f61c6860b2439c4e5afa19e1d15464 Mon Sep 17 00:00:00 2001
From: rtrimana <rtrimana@uci.edu>
Date: Tue, 5 Jul 2016 09:24:23 -0700
Subject: [PATCH] Completing login and key management (part 1.1)

---
 doc/iotcloud.tex | 51 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/doc/iotcloud.tex b/doc/iotcloud.tex
index acad12b..f1a472a 100644
--- a/doc/iotcloud.tex
+++ b/doc/iotcloud.tex
@@ -20,6 +20,57 @@ hash2(user id | password)
 Server has finite length queue of entries + max\_entry\_identifier +
 server login key
 
+\textbf{Login}
+\begin{enumerate}
+\item In the beginning, there are $d$ devices. Each of the 
+devices has a randomly/user-chosen self-generated $m$-bit user 
+identification $i$ and $n$-bit password $p$.
+\item Each device registers these $i$ and $p$ with the server. 
+The server appends ‘salt’ values, $k$-bit random strings $s1$ 
+and $s2$, and generate hash values $j=h(i+s1)$ and 
+$o=h(p+s2)$ for each $i$ and $p$. All $s1$, $s2$, $j$ and $o$ 
+are then stored in the database.
+\item Device to server validation is done by checking the hash values 
+$j\textsc{\char13}$ and $o\textsc{\char13}$ from $i\textsc{\char13}$ and 
+$p\textsc{\char13}$ that are given by users at login time against 
+$i$ and $p$ that are stored in the database.
+\end{enumerate}
+
+\textbf{Symmetric Keys}
+\begin{enumerate}
+\item In the beginning, there are $d$ devices. Each of the 
+devices has a randomly/user-chosen self-generated $m$-bit user 
+identification $i$ and $n$-bit password $p$. These $i$ and $p$ 
+are used for device login on server.
+\item All of $d$ agree on a hash function $h$ that is not known by 
+the server.
+\item A symmetric key for each device is generated by applying $h$
+to the value $(i + p)$ that gives $SK=h(i + p)$.
+\item This value $SK$ is pre-known and pre-stored by all other 
+devices prior to operation of the data structure.
+\end{enumerate}
+
+\textbf{Data Structure on Server}
+\begin{enumerate}
+\item Server maintains a finite length $q$-entry FIFO queue 
+$Q=\{0, 1, …, q-1\}$. It has a head and a tail pointers that keep track 
+of head and tail slots.
+\item Server records a max entry identifier $max$ as a limit for $q$. 
+It keeps track that $q \leq max$ at all times. When $q=max$, the queue 
+mechanism allows this sequence of events when there is a new slot added:
+\begin{enumerate}
+\item Pointer for entry $0$ now points to entry $1$, making it the new 
+entry $0$.
+\item Entry $0$ is expunged from the queue.
+\item New entry is added to the end of the queue, making it entry $q$.
+\item Pointer for entry $q-1$ is advanced to entry $q$, making it the new 
+entry $q-1$.
+\end{enumerate}
+\item For client login, server maintains a table with values $i$, $p$,
+$s1$, and $s2$ that are generated when device registers itself on server 
+for the first time.
+\end{enumerate}
+
 \subsection{Entry layout}
 Each entry has:
 \begin{enumerate}
-- 
2.34.1