slides/slides05.tex
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   475 \end{itemize}
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   482 \frametitle{Best Practices}
   481 \frametitle{Best Practices}
   483 
   482 
   484 {\bf Principle 1:} Every message should say what it means: the interpretation of 
   483 {\bf Principle 1:} Every message should say what it means: the
   485 a message should not depend on the context.\bigskip\pause
   484 interpretation of a message should not depend on the
   486 
   485 context.\bigskip\pause
   487 {\bf Principle 2:} If the identity of a principal is essential to the meaning of a message, it is prudent 
   486 
   488 to mention the principal’s name explicitly in the message (though difficult).\bigskip
   487 {\bf Principle 2:} If the identity of a principal is essential
   489 
   488 to the meaning of a message, it is prudent to mention the
   490 
   489 principal’s name explicitly in the message (though
   491 \end{frame}}
   490 difficult).\bigskip
       
   491 
       
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   518 
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   520 \begin{frame}[c]
   521 \begin{frame}[c]
   521 \frametitle{Best Practices}
   522 \frametitle{Best Practices}
   522 
   523 
   523 {\bf Principle 4:} The protocol designer should know which trust relations his protocol depends on, and why the dependence is necessary. The reasons for particular trust relations being acceptable should be explicit though they will be founded on judgment and policy rather than on logic.\bigskip
   524 {\bf Principle 4:} The protocol designers should know which
   524 
   525 trust relations their protocol depends on, and why the
   525 
   526 dependence is necessary. The reasons for particular trust
   526 Example Certification Authorities: CAs are trusted to certify a key only after proper steps 
   527 relations being acceptable should be explicit though they will
   527 have been taken to identify the principal that owns it.
   528 be founded on judgment and policy rather than on
       
   529 logic.\bigskip
       
   530 
       
   531 
       
   532 Example Certification Authorities: CAs are trusted to certify
       
   533 a key only after proper steps have been taken to identify the
       
   534 principal that owns it.
   528 
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   537 Ross Anderson about the use of Logic:\bigskip
   544 Ross Anderson about the use of Logic:\bigskip
   538 
   545 
   539 \begin{quote}
   546 \begin{quote}
   540 Formal methods can be an excellent way of finding 
   547 Formal methods can be an excellent way of finding 
   541 bugs in security protocol designs as they force the designer 
   548 bugs in security protocol designs as they force the designer 
   542 to make everything explicit and thus confront dif$\!$ficult design 
   549 to make everything explicit and thus confront difficult design 
   543 choices that might otherwise be fudged. 
   550 choices that might otherwise be fudged. 
   544 \end{quote}
   551 \end{quote}
   545 
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