Access of attackers to system parts

1 Access of Attackers to System Parts Locality as a Security Property 

The model of the access of attackers to system parts reflects locality, like the minimal structural requirements  

Whenever a requirement of a certain interest group is considered, only the entities belonging to this interest group are assumed to be correct. 

This was already anticipated in Section 5.2.1, Why Interest Groups . Recall that an interest group is formally a set of identities, and that the entities belonging to it are those that are directly connected to the access points with these identities. This may be called the standard attacker model of cryptology. Combined with suitably small interest groups, it may also be called the standard trust model. 

The intuitive justification for this model is that people are regarded as (potentially) mutually distrusting, i.e., the designer of a signature scheme should not force them to trust others with respect to their authenticated messages, and that no mutually trusted hardware is assumed (see Section 1.3, No Trusted Third Parties ).  

---

With some cryptologic schemes, the access of attackers to system parts is restricted in other ways, e.g., to less than 1/3 of the entities. However, for all schemes with legal relevance, locality as a security property is important. 

Moreover, the access of attackers to system parts was defined once and for all. (More generally, different versions could be distinguished in degree.) Hence, for each interest group i group of the correct type, let... 

Furthermore, the port structure of an attacker that can communicate with such a system is known from the access of attackers to system parts and the model of honest users. Thus one has a class... 

How is the attacker connected to the rest of the system In more intuitive words To which parts of the system does the attacker have access, or, in distributed systems, how many participants may be dishonest Is this constant throughout the lifetime of a system Naturally, the answers depend on the type of systems considered. 

Some parts of a behaviour are of particular interest One is the restriction of the actions to those at the interface, i.e., the service. Another is the restriction to a given set of access points, because that may be what a set of honest users sees from the system. The view of an attacker is the restriction of a run to everything the attacker... 

---