Dolev-Yao model

The Dolev-Yao model is a formal model used to prove properties of interactive protocols.

Contents

The network

The network is represented by a set of abstract machines that can exchange messages. These messages consist of formal terms.

The adversary

The adversary in this model can overhear, intercept, and synthesise any message and is only limited by the constraints of the cryptographic methods used. In other words: "the attacker carries the message."

This omnipotence has been very difficult to model and many threat models simplify it, as, for example, the attacker in ubiquitous computing.

The algebraic model

Cryptographic primitives are modeled by abstract operators. For example, asymmetric encryption for a user x is represented by the encryption function E_x and the decryption function D_x. Their main properties are that their composition is the identity function (D_x E_x = E_x D_x = 1) and that an encrypted message E_x(M) reveals nothing about M. Unlike in the real world, the adversary can neither manipulate the encryption's bit representation nor guess the key.

See also

References