Security is a key component for information technologies and communication. Among the security threats, a very important one is certainly due to vulnerabilities of the integrated circuits that implement cryptographic algorithms to ensure confidentiality, authentication or data integrity (such as smartcards). Among them, the attacks that require a physical access to the circuit, also called “hardware attacks”, enable to retrieve the cryptographic material (such as ``keys'') in a really efficient and powerful way. There are two main kinds of such attacks. The first one, called “side channel attacks”, consists in observing some physical characteristics (such as power consumption or electromagnetic radiation) which are modified during the circuit's computation. The second technique, called “fault attacks”, consists in disrupting the circuit's behavior. Our work is, to our knowledge, the first attempt to describe these two kinds of attacks, which seem very different at first sight, with a common formalism, i.e. with a small set of concepts and algorithms.In the first part of the talk, the side channel and fault attacks will be shortly presented. Next, the concepts and the algorithms which are common to these attacks will be detailed. Then, we’ll show that our proposed formalism easily fits with several representative examples (such as DPA, DFA, DBA, FSA, etc.). At last, the perspectives of our work will be highlighted. For example, we plan to define ``new'' attacks as new combinations of the concepts and the algorithms of our formalism. Then, we plan to provide efficient and modular implementation of these attacks. The long-term aim of this work is to merge the advantages of attack-specific protections to enable a more generic set of countermeasures.