Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Soft Constraint Programming to Analysing Security Protocols   Security protocols stipulate how the remote principals of a computer network
should interact in order to obtain specific security goals. The crucial goals
of confidentiality and authentication may be achieved in various forms, each of
different strength. Using soft (rather than crisp) constraints, we develop a
uniform formal notion for the two goals. They are no longer formalised as mere
yes/no properties as in the existing literature, but gain an extra parameter,
the security level. For example, different messages can enjoy different levels
of confidentiality, or a principal can achieve different levels of
authentication with different principals.
  The goals are formalised within a general framework for protocol analysis
that is amenable to mechanisation by model checking. Following the application
of the framework to analysing the asymmetric Needham-Schroeder protocol, we
have recently discovered a new attack on that protocol as a form of retaliation
by principals who have been attacked previously. Having commented on that
attack, we then demonstrate the framework on a bigger, largely deployed
protocol consisting of three phases, Kerberos.

6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas