pow, audio and ip

.gitignore

@@ -4,3 +4,4 @@ paper.blg
 paper.dvi
 paper.log 
 paper.pdf 
+texput.log

analysis/audio-based.tex

@@ -0,0 +1,31 @@
+\subsection{Audio}
+
+\subsubsection{Privacy}
+Excellent\\
+Audio CAPTCHA doesn't employ any tracking elements and works when used in anonymous
+networks like TOR\@.
+
+\subsubsection{Effectiveness}
+Bad\\
+
+There are browser extensions available to bypass audio CAPTCHAs.
+
+% TODO cite CAPTCHA farm cost analysis paper
+ease.
+\subsubsection{Accessibility}
+Bad\\
+
+Audio CAPTCHAs are inaccessible to non-English speaking users and users with
+auditory disabilities.
+
+\subsubsection{Accuracy}
+Bad\\
+
+Success and failure are absolute states in this method. A solution that doesn't
+match the audio content results in failure while a match is considered a
+success. But when above-mentioned circumvention methods are used, there will be
+results will be completely inaccurate and as the system lacks any adaptational
+capabilities, the failure will be long-lasting.  
+
+The method uses only challenge solutions in its decision process. No other
+external factors are involved.

analysis/context.tex

@@ -32,5 +32,5 @@ success. But when above-mentioned circumvention methods are used, there will be
 results will be completely inaccurate and as the system lacks any adaptational
 capabilities, the failure will be long-lasting.  
 
-The method uses only challenge answers in its decision process. No other
+The method uses only challenge solutions in its decision process. No other
 external factors are involved.

analysis/ip-based.tex

@@ -0,0 +1,37 @@
+\subsection{IP tracking-based}
+
+\subsubsection{Privacy}
+Bad\\
+IP tracking poses privacy threats to users who prefer to be anonymous. Also,
+when accessing a service via a VPN like TOR, IP tracking produces false
+positives.
+
+\subsubsection{Effectiveness}
+Bad\\
+
+Infected computers around the world are used as botnets. So attackers have
+access to a wide range of burnable IP addresses. In such cases, IP tracking-based   
+solutions result in total failure.
+
+Also, due to IPv4 exhaustion and the slow adoption of IPv6, several users access
+the internet through Network Address Translation (NAT) routing. In such cases, a
+single IP can represent thousands of users. If the system relies on IP
+based-tracking entirely for its decision making process, then it will have to
+introduce relaxation rules to accommodate users behind NAT, which reduces it's
+effectiveness.
+
+Both of these attacks are practical.
+
+% TODO cite CAPTCHA farm cost analysis paper
+ease.
+\subsubsection{Accessibility}
+Bad\\
+
+Without relaxation rules for NAT users, unassuming users will be falsely flagged as
+malicious and will dramatically affect their accessibility to the service.
+
+\subsubsection{Accuracy}
+Bad\\
+
+This method does not produce accurate results when it encounters users behind
+NATs or VPNs.

analysis/main.tex

@@ -2,3 +2,6 @@
 \input{analysis/align-obj.tex}
 \input{analysis/blur-text.tex}
 \input{analysis/context.tex}
+\input{analysis/ip-based.tex}
+\input{analysis/audio-based.tex}
+\input{analysis/pow.tex}

analysis/pow.tex

@@ -0,0 +1,39 @@
+\subsection{Proof of Work}
+
+\subsubsection{Privacy}
+Excellent\\
+Proof of Work (PoW) doesn't use any tracking elements and are able to work
+in anonymous networks like TOR\@.
+
+\subsubsection{Effectiveness}
+Excellent\\
+
+Proofs are cryptographically sound and can't be forged. PoW works on the idea
+that the work done to send a request must be more than the work done to respond
+to it. Therefore, a successful attack will require the attacker to dedicate
+significantly more resources than what the service provider uses to run the
+service.
+
+% TODO cite CAPTCHA farm cost analysis paper
+ease.
+\subsubsection{Accessibility}
+Good\\
+
+The process is fully automated so doesn't require any user interactions. So it
+is ideal for users with auditory, cognitive and visual disabilities. But it
+poses challenges to users with slower devices. Some PoW implementations
+time-to-live (TTL) on challenges so when a device is not able to generate proofs
+within that period, their solution will be rejected and will be bared from
+accessing the service.
+
+\subsubsection{Accuracy}
+Good\\
+
+Success and failure are absolute states in this method. A proof that doesn't
+pass verification will be rejected and the user barred from accessing the
+service. But when above-mentioned circumvention methods are used, there will be
+results will be completely inaccurate and as the system lacks any adaptational
+capabilities, the failure will be long-lasting.  
+
+The method uses only challenge proofs in its decision process. No other
+external factors are involved.

paper.tex

@@ -13,6 +13,5 @@
 \input{pre-req/main.tex}
 \input{analysis/main.tex}
 
-
 \input{conclusion.tex}
 \end{document}