ChengsongTanPhdThesis/Chapters/Introduction.tex
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  1243 maintained.
  1243 maintained.
  1244 \end{itemize}
  1244 \end{itemize}
  1245 \noindent
  1245 \noindent
  1246 With a formal finiteness bound in place,
  1246 With a formal finiteness bound in place,
  1247 we can greatly reduce the attack surface of servers in terms of ReDoS attacks.
  1247 we can greatly reduce the attack surface of servers in terms of ReDoS attacks.
       
  1248 The Isabelle/HOL code for our formalisation can be 
       
  1249 found at
       
  1250 \begin{center}
       
  1251 \url{https://github.com/hellotommmy/posix}
       
  1252 \end{center}
  1248 Further improvements to the algorithm with an even stronger version of 
  1253 Further improvements to the algorithm with an even stronger version of 
  1249 simplification can be made.
  1254 simplification can be made. We conjecture that the resulting size of derivatives
       
  1255 can be bounded by a cubic bound w.r.t. the size of the regular expression.
       
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  1265 simplifications fail to simplify. We therefore introduce our version of the
  1272 simplifications fail to simplify. We therefore introduce our version of the
  1266 algorithm with simplification and 
  1273 algorithm with simplification and 
  1267 its correctness proof .  
  1274 its correctness proof .  
  1268 In chapter \ref{Finite} we give the second guarantee
  1275 In chapter \ref{Finite} we give the second guarantee
  1269 of our bitcoded algorithm, that is a finite bound on the size of any 
  1276 of our bitcoded algorithm, that is a finite bound on the size of any 
  1270 regular expression's derivatives.
  1277 regular expression's derivatives. 
       
  1278 We also show how one can extend the
       
  1279 algorithm to include bounded repetitions. 
  1271 In chapter \ref{Cubic} we discuss stronger simplification rules which 
  1280 In chapter \ref{Cubic} we discuss stronger simplification rules which 
  1272 improve the finite bound to a polynomial bound, and also show how one can extend the
  1281 improve the finite bound to a cubic bound.%and the NOT regular expression.
  1273 algorithm to include bounded repetitions. %and the NOT regular expression.
       
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