scale and align-obj analysis complete

analysis/_base.tex

@@ -0,0 +1,6 @@
+\subsection{% NAME}
+\subsubsection{Privacy}
+\subsubsection{Effectiveness}
+\subsubsection{Accessibility}
+\subsubsection{Accuracy}
+\subsubsection{Privacy}

analysis/align-obj.tex

@@ -1,17 +1,28 @@
 \subsection{Align Object}
+
 \subsubsection{Privacy}
 Excellent\\
-The method doesn't on any tracking elements in it's decision process.
+The method doesn't employ any tracking elements and works when used in anonymous
+networks like TOR\@.
 
 \subsubsection{Effectiveness}
-Good\\
+Bad\\
 The method relies on Optical Character Recognition (OCR) capabilities of human
 users. OCR technology is becoming increasingly sophisticated which would render
 this method ineffective in the future.
 
 Without OCR, this method can be bypassed using human-powered CAPTCHA farms with
 % TODO cite CAPTCHA farm cost analysis paper
-ease. On an average, farms generate one CAPTCHA solution every 40 seconds
+ease.
 \subsubsection{Accessibility}
+Bad\\
+Since the method relies on OCR, it is inaccessible to users with visual and
+cognitive disabilities.
 \subsubsection{Accuracy}
-\subsubsection{Privacy}
+Good\\
+Success and failure are absolute states in this method. A misaligned object
+results in failure while a properly aligned object succeeds. But when using
+employing CAPTCHA farms for circumvention, the method fails absolutely.
+
+The method uses only the object alignment in its decision process. No other
+external factors are involved.

intro/intro.tex

@@ -34,6 +34,7 @@ The rest of this paper, rates different CAPTCHA mechanisms and systems based on
 parameters mentioned below and describe how mCaptcha overcomes some of
 them. 
 
+\input{intro/scale.tex}
 % ==================================================
 %					Parameters
 % ==================================================

intro/methods.tex

@@ -1,11 +1,11 @@
 \subsection{CAPTCHA methods analysed}
-We analysed at the following CAPTCHA methods using the above mentioned
+We analysed at the following CAPTCHA methods using the above-mentioned
 parameters. These are popular methods are currently in deployment.
 %TODO add images
 
 \subsubsection{Align object}
 Objects in various degrees of misalignments are displayed to the user and are
-asked to chose the one that is perfectly aligned.
+asked to choose the one that is perfectly aligned.
 		% Example GitHub/Kik inverted Hipop
 
 \subsubsection{Blurred Text}

intro/params.tex

@@ -1,8 +1,9 @@
 \subsection{CAPTCHA rating parameters}
 CAPTCHA systems use a variety of methods in their decision process. Every method
-has it's own strengths and limitations but the following parameters have been
+has its own strengths and limitations, but the following parameters have been
 chosen to uniformly rate CAPTCHA methods and systems in an attempt to compare
 them.
+
 \begin{description}[\IEEEsetlabelwidth{Effectiveness}]
 \item[Privacy] 
 	\begin{itemize}
@@ -12,9 +13,9 @@ them.
 \item[Effectiveness]
 	\begin{itemize}
 		\item Is the method/system effective in containing DoS attacks? 
-		\item Can the method be circumvented? If yes, how practical/feasible
-		the attack?
-
+		\item Can the method be circumvented? If yes, how practical or feasible
+			is the attack? If the method has feasible or practical
+			circumventions, it is immediately marked `bad' for effectiveness.
 	\end{itemize}
 \item[Accessibility]
 	\begin{itemize}
@@ -24,10 +25,14 @@ them.
 		\item Does the method have a language dependency which poses a challenge to
 		non-English speakers?
 	\end{itemize}
+	If a method is impossible to use for any group of users, some of which are
+	mentioned above, 
 \item[Accuracy]
 	\begin{itemize}
 		\item How accurate is the method in detecting potentially malicious
 			users?
 		\item Are there any factors that method's impact accuracy?
 	\end{itemize}
+	Bad accuracy when circumventions are used results downgrades `good' to `bad'
+	rating.
 \end{description}

intro/scale.tex

@@ -0,0 +1,7 @@
+\subsection{Ratings scale}
+There are three levels of ratings:
+\begin{description}[\IEEEsetlabelwidth{Excellent}]
+	\item[Excellent] The method is flawless for all practical purposes.
+	\item[Good] The method is flawed but within acceptable norms.
+	\item[Bad] The method is flawed to a point where it shouldn't be used.
+\end{description}

pre-req/captcha-farms.tex

@@ -1,9 +1,9 @@
 \subsection{CAPTCHA farms}
 CAPTCHA farms are run using cheap labor available in third-world countries. When
-an attacker seeks the services of a CAPTCHA farm, they are provided access to an
+an attacker seeks the services of a CAPTCHA farm, they are provided access to a
 web API to forward CAPTCHA challenges. A labourer working in the farm solves the
 CAPTCHA and the API responds with the solution. The whole process takes less
-then a minute to complete and costs only a fraction of what premium services
+than a minute to complete and costs only a fraction of what premium services
 like reCAPTCHA charge.
 
 Overall, this attack is very feasible and cheap and is frequently used to bypass