# Security Models

### Module description

Nowadays security is one of the main concern. In a first part we present historical and modern cryptographic mechanisms. After we describe existing models for evaluation the security of cryptographic primitives presented. Then we see how it is possible to use these primitives in order to ensure secure communication over unsecure channels and in an hostile environment, i.e. in presence of an intruder controlling the communication. In order to prove the security or to discover flaws of such protocols we present existing verification technique. We start by the simple case, meaning the passive intruder that can only listen the network. Then we consider the case of an active intruder that can also play and replay some messages. Finally we survey the different models existing in order to obtain a secure access control and we give some hints for programmers by presenting non-interference and side channels attacks.

SET Tools

### Tools Session

#### AVISPA

For Avispa export the following variables in a terminal in your home

export AVISPA_PACKAGE=/usr/local/avispa-1.1

export PATH=$PATH:$AVISPA_PACKAGE

Then an example like this one should work :

avispa /usr/local/avispa-1.1/testsuite/hlpsl/EKE.hlpsl --ofmc

The AVISPA package if you want to install it on your personal computer Avispa1.1

### Scyther

Scyther is avaible here. To use the tool you should execute this command line in a terminal

/usr/local/scyther-linux-v1.1/scyther-gui.py

Source files for the exercices

protocol1.spdl

protocol2.spdl

#### Proverif

Last version of Proverif is avaible here. To use Proverif you have two possible command dending if you protocl is modelled in horn clause or in applied pi calculus. Here you find two examples

/usr/local/proverif1.88/proverif -in horn /usr/local/proverif1.88/examples/horn/secr/needham /usr/local/proverif1.88/proverif -in pi /usr/local/proverif1.88/examples/pi/secr-auth/pineedham-orig

Source file for exercice

needham.horn

### Challenge

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