2. Principle of cryptography based on Euclidean lattices

2.1 Security in cryptography

Construction security is of course at the heart of cryptography, the first difficulty being to define it properly. There are many ways to define the security of a public-key cryptographic scheme. You need to define an attacker model (its capabilities in terms of computing time, computing power, memory, etc.), an attack context (what the attacker has access to), and an objective (the attacker's ultimate goal). This constitutes a security model, which should model real attacks as closely as possible. In general, we consider...