\documentclass[11pt,twoside]{article}\makeatletter

\IfFileExists{xcolor.sty}%
  {\RequirePackage{xcolor}}%
  {\RequirePackage{color}}
\usepackage{colortbl}
\usepackage{wrapfig}
\usepackage{ifxetex}
\ifxetex
  \usepackage{fontspec}
  \usepackage{xunicode}
  \catcode`⃥=\active \def⃥{\textbackslash}
  \catcode`❴=\active \def❴{\{}
  \catcode`❵=\active \def❵{\}}
  \def\textJapanese{\fontspec{Noto Sans CJK JP}}
  \def\textChinese{\fontspec{Noto Sans CJK SC}}
  \def\textKorean{\fontspec{Noto Sans CJK KR}}
  \setmonofont{DejaVu Sans Mono}
  
\else
  \IfFileExists{utf8x.def}%
   {\usepackage[utf8x]{inputenc}
      \PrerenderUnicode{–}
    }%
   {\usepackage[utf8]{inputenc}}
  \usepackage[english]{babel}
  \usepackage[T1]{fontenc}
  \usepackage{float}
  \usepackage[]{ucs}
  \uc@dclc{8421}{default}{\textbackslash }
  \uc@dclc{10100}{default}{\{}
  \uc@dclc{10101}{default}{\}}
  \uc@dclc{8491}{default}{\AA{}}
  \uc@dclc{8239}{default}{\,}
  \uc@dclc{20154}{default}{ }
  \uc@dclc{10148}{default}{>}
  \def\textschwa{\rotatebox{-90}{e}}
  \def\textJapanese{}
  \def\textChinese{}
  \IfFileExists{tipa.sty}{\usepackage{tipa}}{}
\fi
\def\exampleFont{\ttfamily\small}
\DeclareTextSymbol{\textpi}{OML}{25}
\usepackage{relsize}
\RequirePackage{array}
\def\@testpach{\@chclass
 \ifnum \@lastchclass=6 \@ne \@chnum \@ne \else
  \ifnum \@lastchclass=7 5 \else
   \ifnum \@lastchclass=8 \tw@ \else
    \ifnum \@lastchclass=9 \thr@@
   \else \z@
   \ifnum \@lastchclass = 10 \else
   \edef\@nextchar{\expandafter\string\@nextchar}%
   \@chnum
   \if \@nextchar c\z@ \else
    \if \@nextchar l\@ne \else
     \if \@nextchar r\tw@ \else
   \z@ \@chclass
   \if\@nextchar |\@ne \else
    \if \@nextchar !6 \else
     \if \@nextchar @7 \else
      \if \@nextchar (8 \else
       \if \@nextchar )9 \else
  10
  \@chnum
  \if \@nextchar m\thr@@\else
   \if \@nextchar p4 \else
    \if \@nextchar b5 \else
   \z@ \@chclass \z@ \@preamerr \z@ \fi \fi \fi \fi
   \fi \fi  \fi  \fi  \fi  \fi  \fi \fi \fi \fi \fi \fi}
\gdef\arraybackslash{\let\\=\@arraycr}
\def\@textsubscript#1{{\m@th\ensuremath{_{\mbox{\fontsize\sf@size\z@#1}}}}}
\def\Panel#1#2#3#4{\multicolumn{#3}{){\columncolor{#2}}#4}{#1}}
\def\abbr{}
\def\corr{}
\def\expan{}
\def\gap{}
\def\orig{}
\def\reg{}
\def\ref{}
\def\sic{}
\def\persName{}\def\name{}
\def\placeName{}
\def\orgName{}
\def\textcal#1{{\fontspec{Lucida Calligraphy}#1}}
\def\textgothic#1{{\fontspec{Lucida Blackletter}#1}}
\def\textlarge#1{{\large #1}}
\def\textoverbar#1{\ensuremath{\overline{#1}}}
\def\textquoted#1{‘#1’}
\def\textsmall#1{{\small #1}}
\def\textsubscript#1{\@textsubscript{\selectfont#1}}
\def\textxi{\ensuremath{\xi}}
\def\titlem{\itshape}
\newenvironment{biblfree}{}{\ifvmode\par\fi }
\newenvironment{bibl}{}{}
\newenvironment{byline}{\vskip6pt\itshape\fontsize{16pt}{18pt}\selectfont}{\par }
\newenvironment{citbibl}{}{\ifvmode\par\fi }
\newenvironment{docAuthor}{\ifvmode\vskip4pt\fontsize{16pt}{18pt}\selectfont\fi\itshape}{\ifvmode\par\fi }
\newenvironment{docDate}{}{\ifvmode\par\fi }
\newenvironment{docImprint}{\vskip 6pt}{\ifvmode\par\fi }
\newenvironment{docTitle}{\vskip6pt\bfseries\fontsize{22pt}{25pt}\selectfont}{\par }
\newenvironment{msHead}{\vskip 6pt}{\par}
\newenvironment{msItem}{\vskip 6pt}{\par}
\newenvironment{rubric}{}{}
\newenvironment{titlePart}{}{\par }

\newcolumntype{L}[1]{){\raggedright\arraybackslash}p{#1}}
\newcolumntype{C}[1]{){\centering\arraybackslash}p{#1}}
\newcolumntype{R}[1]{){\raggedleft\arraybackslash}p{#1}}
\newcolumntype{P}[1]{){\arraybackslash}p{#1}}
\newcolumntype{B}[1]{){\arraybackslash}b{#1}}
\newcolumntype{M}[1]{){\arraybackslash}m{#1}}
\definecolor{label}{gray}{0.75}
\def\unusedattribute#1{\sout{\textcolor{label}{#1}}}
\DeclareRobustCommand*{\xref}{\hyper@normalise\xref@}
\def\xref@#1#2{\hyper@linkurl{#2}{#1}}
\begingroup
\catcode`\_=\active
\gdef_#1{\ensuremath{\sb{\mathrm{#1}}}}
\endgroup
\mathcode`\_=\string"8000
\catcode`\_=12\relax

\usepackage[a4paper,twoside,lmargin=1in,rmargin=1in,tmargin=1in,bmargin=1in,marginparwidth=0.75in]{geometry}
\usepackage{framed}

\definecolor{shadecolor}{gray}{0.95}
\usepackage{longtable}
\usepackage[normalem]{ulem}
\usepackage{fancyvrb}
\usepackage{fancyhdr}
\usepackage{graphicx}
\usepackage{marginnote}

\renewcommand{\@cite}[1]{#1}


\renewcommand*{\marginfont}{\itshape\footnotesize}

\def\Gin@extensions{.pdf,.png,.jpg,.mps,.tif}

  \pagestyle{fancy}

\usepackage[pdftitle={Cryptanalysis and Further Improvement of a Dynamic ID and Smart Card based Remote user Authentication Scheme},
 pdfauthor={}]{hyperref}
\hyperbaseurl{}

	 \paperwidth210mm
	 \paperheight297mm
              
\def\@pnumwidth{1.55em}
\def\@tocrmarg {2.55em}
\def\@dotsep{4.5}
\setcounter{tocdepth}{3}
\clubpenalty=8000
\emergencystretch 3em
\hbadness=4000
\hyphenpenalty=400
\pretolerance=750
\tolerance=2000
\vbadness=4000
\widowpenalty=10000

\renewcommand\section{\@startsection {section}{1}{\z@}%
     {-1.75ex \@plus -0.5ex \@minus -.2ex}%
     {0.5ex \@plus .2ex}%
     {\reset@font\Large\bfseries}}
\renewcommand\subsection{\@startsection{subsection}{2}{\z@}%
     {-1.75ex\@plus -0.5ex \@minus- .2ex}%
     {0.5ex \@plus .2ex}%
     {\reset@font\Large}}
\renewcommand\subsubsection{\@startsection{subsubsection}{3}{\z@}%
     {-1.5ex\@plus -0.35ex \@minus -.2ex}%
     {0.5ex \@plus .2ex}%
     {\reset@font\large}}
\renewcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
     {-1ex \@plus-0.35ex \@minus -0.2ex}%
     {0.5ex \@plus .2ex}%
     {\reset@font\normalsize}}
\renewcommand\subparagraph{\@startsection{subparagraph}{5}{\parindent}%
     {1.5ex \@plus1ex \@minus .2ex}%
     {-1em}%
     {\reset@font\normalsize\bfseries}}


\def\l@section#1#2{\addpenalty{\@secpenalty} \addvspace{1.0em plus 1pt}
 \@tempdima 1.5em \begingroup
 \parindent \z@ \rightskip \@pnumwidth 
 \parfillskip -\@pnumwidth 
 \bfseries \leavevmode #1\hfil \hbox to\@pnumwidth{\hss #2}\par
 \endgroup}
\def\l@subsection{\@dottedtocline{2}{1.5em}{2.3em}}
\def\l@subsubsection{\@dottedtocline{3}{3.8em}{3.2em}}
\def\l@paragraph{\@dottedtocline{4}{7.0em}{4.1em}}
\def\l@subparagraph{\@dottedtocline{5}{10em}{5em}}
\@ifundefined{c@section}{\newcounter{section}}{}
\@ifundefined{c@chapter}{\newcounter{chapter}}{}
\newif\if@mainmatter 
\@mainmattertrue
\def\chaptername{Chapter}
\def\frontmatter{%
  \pagenumbering{roman}
  \def\thechapter{\@roman\c@chapter}
  \def\theHchapter{\roman{chapter}}
  \def\thesection{\@roman\c@section}
  \def\theHsection{\roman{section}}
  \def\@chapapp{}%
}
\def\mainmatter{%
  \cleardoublepage
  \def\thechapter{\@arabic\c@chapter}
  \setcounter{chapter}{0}
  \setcounter{section}{0}
  \pagenumbering{arabic}
  \setcounter{secnumdepth}{6}
  \def\@chapapp{\chaptername}%
  \def\theHchapter{\arabic{chapter}}
  \def\thesection{\@arabic\c@section}
  \def\theHsection{\arabic{section}}
}
\def\backmatter{%
  \cleardoublepage
  \setcounter{chapter}{0}
  \setcounter{section}{0}
  \setcounter{secnumdepth}{2}
  \def\@chapapp{\appendixname}%
  \def\thechapter{\@Alph\c@chapter}
  \def\theHchapter{\Alph{chapter}}
  \appendix
}
\newenvironment{bibitemlist}[1]{%
   \list{\@biblabel{\@arabic\c@enumiv}}%
       {\settowidth\labelwidth{\@biblabel{#1}}%
        \leftmargin\labelwidth
        \advance\leftmargin\labelsep
        \@openbib@code
        \usecounter{enumiv}%
        \let\p@enumiv\@empty
        \renewcommand\theenumiv{\@arabic\c@enumiv}%
	}%
  \sloppy
  \clubpenalty4000
  \@clubpenalty \clubpenalty
  \widowpenalty4000%
  \sfcode`\.\@m}%
  {\def\@noitemerr
    {\@latex@warning{Empty `bibitemlist' environment}}%
    \endlist}

\def\tableofcontents{\section*{\contentsname}\@starttoc{toc}}
\parskip0pt
\parindent1em
\def\Panel#1#2#3#4{\multicolumn{#3}{){\columncolor{#2}}#4}{#1}}
\newenvironment{reflist}{%
  \begin{raggedright}\begin{list}{}
  {%
   \setlength{\topsep}{0pt}%
   \setlength{\rightmargin}{0.25in}%
   \setlength{\itemsep}{0pt}%
   \setlength{\itemindent}{0pt}%
   \setlength{\parskip}{0pt}%
   \setlength{\parsep}{2pt}%
   \def\makelabel##1{\itshape ##1}}%
  }
  {\end{list}\end{raggedright}}
\newenvironment{sansreflist}{%
  \begin{raggedright}\begin{list}{}
  {%
   \setlength{\topsep}{0pt}%
   \setlength{\rightmargin}{0.25in}%
   \setlength{\itemindent}{0pt}%
   \setlength{\parskip}{0pt}%
   \setlength{\itemsep}{0pt}%
   \setlength{\parsep}{2pt}%
   \def\makelabel##1{\upshape ##1}}%
  }
  {\end{list}\end{raggedright}}
\newenvironment{specHead}[2]%
 {\vspace{20pt}\hrule\vspace{10pt}%
  \phantomsection\label{#1}\markright{#2}%

  \pdfbookmark[2]{#2}{#1}%
  \hspace{-0.75in}{\bfseries\fontsize{16pt}{18pt}\selectfont#2}%
  }{}
      \def\TheFullDate{2016 2016-01-15 (revised: 34 Year 2016 15 January 2016)}
\def\TheID{\makeatother }
\def\TheDate{2016 2016-01-15}
\title{Cryptanalysis and Further Improvement of a Dynamic ID and Smart Card based Remote user Authentication Scheme}
\author{}\makeatletter 
\makeatletter
\newcommand*{\cleartoleftpage}{%
  \clearpage
    \if@twoside
    \ifodd\c@page
      \hbox{}\newpage
      \if@twocolumn
        \hbox{}\newpage
      \fi
    \fi
  \fi
}
\makeatother
\makeatletter
\thispagestyle{empty}
\markright{\@title}\markboth{\@title}{\@author}
\renewcommand\small{\@setfontsize\small{9pt}{11pt}\abovedisplayskip 8.5\p@ plus3\p@ minus4\p@
\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus2\p@
\belowdisplayshortskip 4\p@ plus2\p@ minus2\p@
\def\@listi{\leftmargin\leftmargini
               \topsep 2\p@ plus1\p@ minus1\p@
               \parsep 2\p@ plus\p@ minus\p@
               \itemsep 1pt}
}
\makeatother
\fvset{frame=single,numberblanklines=false,xleftmargin=5mm,xrightmargin=5mm}
\fancyhf{} 
\setlength{\headheight}{14pt}
\fancyhead[LE]{\bfseries\leftmark} 
\fancyhead[RO]{\bfseries\rightmark} 
\fancyfoot[RO]{}
\fancyfoot[CO]{\thepage}
\fancyfoot[LO]{\TheID}
\fancyfoot[LE]{}
\fancyfoot[CE]{\thepage}
\fancyfoot[RE]{\TheID}
\hypersetup{citebordercolor=0.75 0.75 0.75,linkbordercolor=0.75 0.75 0.75,urlbordercolor=0.75 0.75 0.75,bookmarksnumbered=true}
\fancypagestyle{plain}{\fancyhead{}\renewcommand{\headrulewidth}{0pt}}

\date{}
\usepackage{authblk}

\providecommand{\keywords}[1]
{
\footnotesize
  \textbf{\textit{Index terms---}} #1
}

\usepackage{graphicx,xcolor}
\definecolor{GJBlue}{HTML}{273B81}
\definecolor{GJLightBlue}{HTML}{0A9DD9}
\definecolor{GJMediumGrey}{HTML}{6D6E70}
\definecolor{GJLightGrey}{HTML}{929497} 

\renewenvironment{abstract}{%
   \setlength{\parindent}{0pt}\raggedright
   \textcolor{GJMediumGrey}{\rule{\textwidth}{2pt}}
   \vskip16pt
   \textcolor{GJBlue}{\large\bfseries\abstractname\space}
}{%   
   \vskip8pt
   \textcolor{GJMediumGrey}{\rule{\textwidth}{2pt}}
   \vskip16pt
}

\usepackage[absolute,overlay]{textpos}

\makeatother 
      \usepackage{lineno}
      \linenumbers
      
\begin{document}

             \author[1]{Narendra  Panwar}

             \affil[1]{  Uttarakhand Technical University}

\renewcommand\Authands{ and }

\date{\small \em Received: 10 December 2015 Accepted: 3 January 2016 Published: 15 January 2016}

\maketitle


\begin{abstract}
        


Computer systems and their interconnections using networks have im-proved the dependence of both the organizations as well as the individuals on the stored information. This interconnection, in turn, has led to a heightened awareness of the need for data security and the protection of data and re- sources from electronic frauds, electronic eavesdropping, and networkbased attacks. Consequently, cryptography and network security have evolved, leading to the development of smart cards to enforce network security. Re-cently, Rafael Martinez-Pelez and Rico- Novella Francisco [1] pointed out vul-nerabilities in Wang et al. [2] scheme. In this paper, we cryptanalyze Wanget al. scheme and demonstrated that our proposed scheme withstands thevulnerabilities pointed out by Francisco et al. and it completes all the re-cent security requirements of [3]. We implemented the proposed scheme in MATLAB and demonstrated that our proposed scheme is not vulnerable to the shortcomings pointed out by Francisco et al. in their scheme.

\end{abstract}


\keywords{security, authentication, remote user, smart card.}

\begin{textblock*}{18cm}(1cm,1cm) % {block width} (coords) 
\textcolor{GJBlue}{\LARGE Global Journals \LaTeX\ JournalKaleidoscope\texttrademark}
\end{textblock*}

\begin{textblock*}{18cm}(1.4cm,1.5cm) % {block width} (coords) 
\textcolor{GJBlue}{\footnotesize \\ Artificial Intelligence formulated this projection for compatibility purposes from the original article published at Global Journals. However, this technology is currently in beta. \emph{Therefore, kindly ignore odd layouts, missed formulae, text, tables, or figures.}}
\end{textblock*}


\let\tabcellsep& 	 	 		 
\section[{Introduction}]{Introduction}\par
n 1981, a remote password authentication scheme was proposed by L. Lamport \hyperref[b2]{[4]} over an insecure channel. Since then, several schemes \hyperref[b3]{[5]}, \hyperref[b4]{[6]}, \hyperref[b5]{[7]}, \hyperref[b6]{[8]}, \hyperref[b7]{[9]}, \hyperref[b8]{[10]} have been proposed to address this problem for achieving more functionality and efficiency. In a traditional password scheme, each user has an identity and a secret password. If a person wants to log into a network system, they must submit their identity and the corresponding password.\par
To avoid storing a plain password table in a public network system, several scheme \hyperref[b2]{[4]}, \hyperref[b9]{[11]}, \hyperref[b10]{[12]} have proposed a dictionary of verification tables to store each user ID and the corresponding one-way hash value of passwords in the remote system. In 2005, Chien et al. \hyperref[b7]{[9]} pointed out that Das et al. \hyperref[b6]{[8]} scheme cannot achieve user anonymity because an attacker can trace user with the static value. In 2010, Lee et al. \hyperref[b11]{[13]} have analyzed the security of the smart card based user authentication scheme proposed by Lee and Chiu \hyperref[b12]{[14]}. Their security analysis showed that scheme \hyperref[b7]{[9]} does not achieve its main security goal of the two-factor security. To demonstrate this, they have shown that the scheme is vulnerable to an o\textunderscore -line dictionary attack in which an attacker, who has obtained the secret values stored in the users smart card can easily find out its password. Besides reporting the security problem, they showed what really is causing the problem and how to fix it and they proposed a new and improved scheme than Lee and Chius scheme.\par
In 2012, Francisco et al. have shown security vulnerabilities like Denial of service, server spoong, impersonation in Wang et al.  {\ref [2]} scheme. We propose a scheme that can withstand the above mentioned attacks, we implemented and demonstrated the stated scheme using MATLAB. The paper is organized as follows.\par
In Section 2, we give a brief review on Wang et al.s scheme. We demon-strate the vulnerabilities of the scheme in Section 3. The proposed scheme and its security analysis are presented in section 4 and 5. Section 6 com-pares the performance of our proposed scheme with other related schemes. Finally, we conclude this paper in Section 7.  [ID i ,CID i ,A i ,T] of User U i H(PW i )=A i ?H(x)?ID i CID i *=H(PW i )?H(A i ?y?T*)?ID i Send M i =[ID i ,CID i ,A i ,T*] to S 
\section[{Verification Phase}]{Verification Phase}\par
Verify T*-T? ?T, if time interval is incorrect then reject login request otherwise accept M i and perform:H(PW i )*=CID i ?H(A i ?y?T*)?ID i Compute ID i *=H(PW i )*?H(x)?A i\par
Here ID i * and ID i are equals so login request accepted by the server and S performs:  CID i =H(PW i )?H(A i ?y?T)?ID i Send M i =[ID i ,CID i ,A i ,T] to S.\par
Intercept message M i of User U i M i =[ID i ,CID i ,A i ,T] Compute H(x)=H(PW a )?A a ?ID a Compute H(PW i )=A i ?H(x)?ID i 
\section[{Proposed Scheme}]{Proposed Scheme}\par
This section proposes a strong, secure authentication scheme which will with-stand the security vulnerabilities which leads to the aforementioned attacks. 
\section[{a) Registration phase}]{a) Registration phase}\par
In this phase, the user registers with the remote server S through a secure channel to be a authentic user.\par
Step 1: chooses his/her identity and password and computes\par
. Then sends the registration request\par
Step 2: Upon receiving from , S veri\textunderscore es the validity of and computes\par
Step 3: computes then captures current date and time in T and create a record in its database.\par
Step 4: stores into the smart card of and sends the smart card through a secure channel to the user\par
Step 5: Upon receiving the smart card from stores into smart card and does not need to remember after \textunderscore nishing registration phase. Finally, smart card contains b) Login phase In this phase, when an authentic user want to login to the remote server S, he/she must perform the following steps:\par
Step 1: inserts his/her smart card into the card reader and inputs the identity and password The smart card computes where is retrieved from its memory space.\par
Step 2: The  Step 1: reveals M 1 by using the Chinese Remainder Theorem (CRT) with p and q to obtain and . Then veri\textunderscore es the revealed with the stored corresponding to ID . If \textunderscore  T, S replaces with new time variable T in its database. Otherwise, rejects login request.\par
Step 2: If Step 1 holds, S computes and checks if computed equals received . If it holds, would successfully authenticate and computes the session key shared with .\par
Step 3: computes and send it to .\par
Step 4: Ui computes M *=H(VIDikRx) and check if computed M * equals received . If it does not hold,i U i U i U i U i U i U i U i U 's, S S S S S S S S S i U i U i U ID i PW i H(IDi PW i R where\par
x Rx number generated by random PW i R x )] to S. i ID H(ID [ PW i R x i ID H(ID [ ] VID i =H(K?ID i ) i =VID i ?H(ID i PW i R x N T , ] R x [H(.),N i T] S , i U [H(.),N i T ] R x , i ID i ID PW i VID i VID i *=N i ?H(ID i PW i R x ), Rx T=T+1 and M 1 =(ID i VID i * R x T) 2 Rx T i Ti Ti T T VID i i U 's, VID i * =H(K?ID i VID i ), k =H(VID i R x S T) . i U 2 =H(VID R x M 1 M2 2 2 M Cryptanalysis andID PW i PW i * k =H(VID i R x T) S S . i U R x * R x 
\section[{Global Journal of Computer Science and Technology}]{Global Journal of Computer Science and Technology}\par
Volume XVI Issue IV Version I ( ) number generated by Then, the smart card V. 
\section[{Security Analysis}]{Security Analysis}\par
In this section, we analyzed the security of the proposed scheme and shown that our scheme is secure against the following well-known attacks. The security of our proposed authentication scheme is based on the secure hash function and the In the following steps, we analyzed the security of the proposed scheme to verify that the specified security requirements \hyperref[b1]{[3]} are fulfilled. a) Resistance to user anonymity attack Suppose that the attacker intercepted authentication messages. Then, the adversary cannot retrieve any static parameter from these messages, due to the . Hence, the proposed scheme can preserve user anonymity. 
\section[{b) Resistance to offine password guessing attack}]{b) Resistance to offine password guessing attack}\par
Suppose that a malicious legitimate attacker user has got smart card, and the secret information and can also be revealed under our assumption of the non-tamper resistant smart card. Even after gathering this information, the attacker has to at least guess both and correctly at the same time, because it has been demonstrated that our scheme can provide identity protection. It is impossible to guess these two parameters correctly at the same time, and thus the proposed scheme can resist offine password guessing attack with smart card security breach. 
\section[{c) Resistance to stolen verifier attack}]{c) Resistance to stolen verifier attack}\par
In the proposed scheme no sensitive verifiers corresponding to the users are maintained by . Therefore, the proposed scheme is free from the stolen verifier attack. Based on the dificulty of the one-way hash algorithm, any previously generated session keys cannot be revealed without knowledge of the and . As a result our scheme provides the property of forward secrecy. 
\section[{VI.}]{VI.} 
\section[{Computational Cost Analysis}]{Computational Cost Analysis}\par
In this scheme we have taken 1.0 unit average run time for a single one-way secure hash function operation. The proposed scheme requires lower computation overhead with comparison to other schemes, which is shown in the Table  {\ref 6} and the Figure  {\ref 1}.  Wang et al.s scheme was proposed for resolving security issues presented in pre-vious work of \hyperref[b6]{[8]}. However, we have discovered some security aws in their scheme making it vulnerable to various attacks such as impersonation, server spoofing and denial of service attack. Moreover, the scheme cannot withstand password change aws. As a remedy to the aforementioned weaknesses, we have presented an enhanced scheme, which overcome the vulnerabilities of \hyperref[b14]{[15]}  i ID i ID VID i VID i i U 's, i U 's, i U 's, . i U . i U M 1 . i U CRT. CRT. R x R x R x PW i . i U , PW i N i N i [H(.),N i T Ua S T . i U H(ID i PW i R x ). 1 =(ID i VID i R x T) 2 M 2 *=H(VID i R x M 2 M . i U S k =H(VID i R x T © 2016 
\section[{B*=H(ID}]{B*=H(ID}i PW i * R x B=H(ID i PW i R x ), *) A i =A i ?B?B*. i A R x i U 's, x * PW i * PW i . i U PW i\begin{figure}[htbp]
\noindent\textbf{}\includegraphics[]{image-2.png}
\caption{\label{fig_0}}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{5}\includegraphics[]{image-3.png}
\caption{\label{fig_1}Table 5 :}\end{figure}
  \begin{figure}[htbp]
\noindent\textbf{1NotationII} \par 
\begin{longtable}{}
\end{longtable} \par
 
\caption{\label{tab_0}Table 1 : Notation Table II .}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{2} \par 
\begin{longtable}{P{0.019642857142857142\textwidth}P{0.33035714285714285\textwidth}P{0.37142857142857144\textwidth}P{0.12857142857142856\textwidth}}
\tabcellsep \multicolumn{3}{l}{Cryptanalysis and Further Improvement of a Dynamic ID and Smart Card based Remote user}\\
\tabcellsep \tabcellsep \multicolumn{2}{l}{Authentication Scheme}\\
\tabcellsep \multicolumn{2}{l}{Symbol Description}\\
\tabcellsep U i\tabcellsep The User\\
\tabcellsep S\tabcellsep The Remote Server\\
\tabcellsep ID i\tabcellsep Unique identity of U i\\
\tabcellsep PW i\tabcellsep Unique password of U i\\
Year 2016\tabcellsep S k\tabcellsep The common session key The bitwise XOR operation\\
26\tabcellsep H(.)\tabcellsep \multicolumn{2}{l}{A collision free one-way hash function such as SHA-256}\\
\tabcellsep x,y\tabcellsep Secret Keys of S\\
\tabcellsep User U i\tabcellsep \tabcellsep Server S\\
\tabcellsep \multicolumn{2}{l}{Registration Phase}\\
\tabcellsep \multicolumn{2}{l}{Select ID i Send ID i to Server S}\tabcellsep Choose PW Sends PW i and Smart Card to U i\\
\tabcellsep \tabcellsep \tabcellsep through secure channel\end{longtable} \par
  {\small\itshape [Note: i Compute A i =H(PW i )?H(x)?ID i Store [A i ,y,H(.)] into Smart Card]} 
\caption{\label{tab_1}Table 2 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{2} \par 
\begin{longtable}{}
\end{longtable} \par
 
\caption{\label{tab_2}Table 2 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{2} \par 
\begin{longtable}{P{0.5289944134078212\textwidth}P{0.32100558659217876\textwidth}}
User U i\tabcellsep Server S\\
Login Phase\tabcellsep \\
U i keys in his/her ID i and PW i into\tabcellsep Verification Phase\\
smart card terminal and perform:\tabcellsep \\
\tabcellsep Verify T*-T ? ? T, if time interval\\
CID i =H(PW i )?H(A i ?y?T)?ID i\tabcellsep is incorrect then reject login request\\
Send M i =[ ID i , CID i , A i ,T ] to S.\tabcellsep otherwise accept M i and perform:\\
\tabcellsep H(PW i )*=CID i ?H(A i ?y?T)?ID i\\
\tabcellsep Compute ID i *=H(PW i )*?H(x)?A i\\
\tabcellsep If ID i *and ID i are not equals,\\
\tabcellsep then reject login request otherwise\\
\tabcellsep S performs:\\
\tabcellsep Computes B= H(H(PW i )*?y?T 2 )\\
\tabcellsep Sends [B, T 2 ] to U i\\
Server Verification Phase\tabcellsep \\
Verify T 2 -T? ?T, if the time interval\tabcellsep \\
is incorrect then U i terminate phase,\tabcellsep \\
otherwise perform:\tabcellsep \\
Computes B*=H(H(PW i ) y T 2 )\tabcellsep \\
If B*=B holds U i confirms\tabcellsep \\
the identity of S.\tabcellsep \\
User U i\tabcellsep Server S\\
Password Change Phase\tabcellsep \\
U i insert smart card into\tabcellsep \\
card reader and keys in his/her PW i ,\tabcellsep \\
new password NPW i and performs:\tabcellsep \\
A i *=A i ?H(PW i )?H(NPW i )\tabcellsep \\
Store A i * into smart card\tabcellsep \\
with replacing A i .\tabcellsep \end{longtable} \par
 
\caption{\label{tab_3}Table 2 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{3} \par 
\begin{longtable}{P{0.7240740740740741\textwidth}P{0.1259259259259259\textwidth}}
Legitimate User (Attacker) U a\tabcellsep Server S\\
Using smart card\tabcellsep \end{longtable} \par
  {\small\itshape [Note: Compute H(x)=H(PW a )?A a ?ID a Intercept previous message]} 
\caption{\label{tab_4}Table 3 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{3} \par 
\begin{longtable}{P{0.38387096774193546\textwidth}P{0.4387096774193548\textwidth}P{0.027419354838709675\textwidth}}
i ID * *\tabcellsep ID * i\\
Ui\tabcellsep \\
\tabcellsep i * A H(x)\tabcellsep y\\
H(x)\tabcellsep \end{longtable} \par
  {\small\itshape [Note: © 2016 Global Journals Inc. (US) 1]} 
\caption{\label{tab_5}Table 3 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{4} \par 
\begin{longtable}{P{0.63125\textwidth}P{0.21874999999999997\textwidth}}
Legitimate User U i\tabcellsep Legitimate User (Attacker) U a as S\\
Login Phase\tabcellsep \\
U i keys in his/her ID i and PW i\tabcellsep \\
into smart card terminal and per-\tabcellsep \\
form:\tabcellsep \end{longtable} \par
 
\caption{\label{tab_6}Table 4 :}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{} \par 
\begin{longtable}{P{0.2701856148491879\textwidth}P{0.5660092807424594\textwidth}P{0.013805104408352668\textwidth}}
Legitimate User U l\tabcellsep Attacker User U a\\
Login Phase\tabcellsep \\
U l keys his/her ID l and PW l into\tabcellsep \\
smart card terminal and perform:\tabcellsep \\
Computes\tabcellsep \\
CID l =H(PW l )?H(A l ?y?T)?ID l\tabcellsep \multicolumn{2}{l}{Intercept message M 1 of User U l}\\
\tabcellsep M1=[ID l ,CID l ,A l ,T]\\
\tabcellsep \multicolumn{2}{l}{Compute H(x)=H(PW a )?A a ?ID a}\\
\tabcellsep Change password\\
\tabcellsep \multicolumn{2}{l}{Compute H(PW l )=A l ?H(x)?ID}\\
\tabcellsep \multicolumn{2}{l}{smart card computes}\\
\tabcellsep \tabcellsep mod n\\
\tabcellsep and sends a login request\tabcellsep to\\
\tabcellsep c) Authentication phase\\
\tabcellsep \multicolumn{2}{l}{Upon receiving the login request M1 from ,}\\
\tabcellsep performs the following steps:\end{longtable} \par
  {\small\itshape [Note: lAttacker user U a computes:A a *=A l ?H(PW l )?H(NPW l )Store A l * into smart card replacing with A l .]} 
\caption{\label{tab_7}}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{} \par 
\begin{longtable}{P{0.6426829268292683\textwidth}P{0.007774390243902438\textwidth}P{0.07515243902439024\textwidth}P{0.09588414634146342\textwidth}P{0.02850609756097561\textwidth}}
Year 2016\tabcellsep \tabcellsep \tabcellsep \\
30\tabcellsep \tabcellsep \tabcellsep \\
\multicolumn{5}{l}{Ui stops the session. Otherwise, Ui now successfully}\\
\multicolumn{3}{l}{authenticate S and use}\tabcellsep \tabcellsep shared\\
\multicolumn{5}{l}{session key with for securing future communications.}\\
\multicolumn{3}{l}{d) Password change phase}\tabcellsep \\
\multicolumn{3}{l}{In this phase, the user}\tabcellsep \multicolumn{2}{l}{inserts the smart card}\\
\multicolumn{2}{l}{into device and inputs}\tabcellsep \multicolumn{2}{l}{, original password i}\tabcellsep , new\\
password\tabcellsep and\tabcellsep *, where\tabcellsep \multicolumn{2}{l}{is a new random}\\
© 2016 Global Journals Inc. (US) 1\tabcellsep \tabcellsep \tabcellsep \end{longtable} \par
 
\caption{\label{tab_8}}\end{figure}
 \begin{figure}[htbp]
\noindent\textbf{} \par 
\begin{longtable}{}
\end{longtable} \par
 
\caption{\label{tab_11}}\end{figure}
 			\footnote{© 2016 Global Journals Inc. (US) 1} 		 		\backmatter  			  				\begin{bibitemlist}{1}
\bibitem[Lee]{b12}\label{b12} 	 		\textit{},  		 			Y.-C Lee 		.  	 	 		\textit{Narn-Yih}  		 	 
\bibitem[Das et al. ()]{b6}\label{b6} 	 		‘A dynamic id-based remote user authentication scheme’.  		 			M Das 		,  		 			V Gulati 		,  		 			A Saxena 		.  		 \xref{http://dx.doi.org/10.1109/TCE.2004.1309441}{10.1109/TCE.2004.1309441}.  	 	 		\textit{IEEE Transactions on Consumer Electronics}  		2004. 50  (2)  p. .  	 
\bibitem[Wang et al. ()]{b0}\label{b0} 	 		‘A more eficient and secure dynamic ID-based remote user authentication scheme’.  		 			J D Y Y Wang 		,  		 			J Y Liu 		,  		 			F X Xiao 		.  	 	 		\textit{Computer Communications}  		2009. 32 p. .  	 
\bibitem[Wu et al. ()]{b8}\label{b8} 	 		‘A Password-Based User Authentication Scheme for the Integrated EPR Information System’.  		 			Z.-Y Wu 		,  		 			Y Chung 		,  		 			F Lai 		,  		 			T.-S Chen 		.  		 \xref{http://dx.doi.org/10.1007/s10916-010-9527-7}{10.1007/s10916-010-9527-7}.  		 \url{http://link.springer.com/10.1007/s10916-010-9527-7}  	 	 		\textit{Journal of Medical Systems}  		2012. 36  (2)  p. .  	 
\bibitem[Liao and Wang ()]{b14}\label{b14} 	 		‘A secure dynamic ID based remote user authentication scheme for multi-server environment’.  		 			Y.-P Liao 		,  		 			S.-S Wang 		.  		 \xref{http://dx.doi.org/10.1016/j.csi.2007.10.007}{10.1016/j.csi.2007.10.007}.  		 \url{http://dx.doi.org/10.1016/j.csi.2007.10.007http://linkinghub.elsevier.com/retrieve/pii/S092054890700103}  	 	 		\textit{Computer Standards \& Interfaces}  		2009. 31  (1)  p. .  	 
\bibitem[Sun ()]{b4}\label{b4} 	 		\textit{An eficient remote use authentication scheme using smart cards},  		 			H.-M Sun 		.  		 \xref{http://dx.doi.org/10.1109/30.920446}{10.1109/30.920446}.  		2000.  	 
\bibitem[Lee et al. ()]{b11}\label{b11} 	 		\textit{Attacking and Improving on Lee and Chiu ' s Authentication Scheme Using Smart Cards},  		 			Y Lee 		,  		 			H Yang 		,  		 			D Won 		.  		2010. Berlin Heidelberg; Berlin, Heidelberg: Springer. p. .  	 
\bibitem[Van Leeuwen ()]{b3}\label{b3} 	 		‘Authentication : A Concise Survey’.  		 			PG M J 		,  		 			J Van Leeuwen 		.  	 	 		\textit{Computers \& Security}  		1986. 5 p. .  	 
\bibitem[Chang and Hwang ()]{b9}\label{b9} 	 		‘Cryptographic authentication of passwords, in: Security Technology’.  		 			C C Chang 		,  		 			S J Hwang 		.  		 \xref{http://dx.doi.org/10.1109/CCST.1991.202203}{10.1109/CCST.1991.202203}.  	 	 		\textit{Proceedings. 25th Annual 1991 IEEE International Carnahan Conference on},  				 (25th Annual 1991 IEEE International Carnahan Conference on)  		1991. 1991. p. .  	 
\bibitem[Chiu ()]{b13}\label{b13} 	 		‘Improved remote authentication scheme with smart card’.  		 			Chiu 		.  	 	 		\textit{Computer Standards and Interfaces}  		2005. 27  (2)  p. .  	 
\bibitem[Lee et al. ()]{b7}\label{b7} 	 		‘Improvement of Chien et al.'s remote user authentication scheme using smart cards’.  		 			S.-W Lee 		,  		 			H.-S Kim 		,  		 			K.-Y Yoo 		.  		 \xref{http://dx.doi.org/10.1016/j.csi.2004.02.002.URL}{10.1016/j.csi.2004.02.002.URL}.  		 \url{http://dx.doi.org/10.1016/j.csi.2004.02.002.URLhttp://www.sciencedirect.com/science/article/pii/S0920548904000170}  	 	 		\textit{Computer Standards \&}  		2005. 27  (2) .  	 
\bibitem[Kumar ()]{b5}\label{b5} 	 		‘New remote user authentication scheme using smart cards’.  		 			M Kumar 		.  		 \xref{http://dx.doi.org/10.1109/TCE.2004.1309433}{10.1109/TCE.2004.1309433}.  	 	 		\textit{IEEE Transactions on Consumer Electronics}  		2004. 50 p. .  	 
\bibitem[Tsai et al. ()]{b1}\label{b1} 	 		‘Password authentication schemes: Current status and key issues’.  		 			C S Tsai 		,  		 			C C Lee 		,  		 			M S Hwang 		.  		 doi:10.1109/ ICM2CS. 2009.5397977.  		 \url{http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=5397977}  	 	 		\textit{International Journal of Network Security}  		2006. IEEE. 3 p. .  	 
\bibitem[Lamport ()]{b2}\label{b2} 	 		‘Password authentication with insecure communication’.  		 			L Lamport 		.  		 \xref{http://dx.doi.org/10.1145/358790.358797}{10.1145/358790.358797}.  		 \url{URLhttp://portal.acm.org/citation.cfm?doid=358790.358797}  	 	 		\textit{Communications of the ACM}  		1981. 24  (11)  p. .  	 
\bibitem[Yen ()]{b10}\label{b10} 	 		‘Security of a one-time signature’.  		 			S.-M Yen 		.  		 \xref{http://dx.doi.org/10.1049/el:19970460}{10.1049/el:19970460}.  	 	 		\textit{Electronics Letters}  		1997. 33  (8)  p. .  	 
\end{bibitemlist}
 			 		 	 
\end{document}
