### C

C is a general-purpose, imperative computer programming language, supporting structured programming, lexical variable scope and recursion, while a static type system prevents many unintended operations.

### C#

C is a general-purpose, imperative computer programming language, supporting structured programming, lexical variable scope and recursion, while a static type system prevents many unintended operations.

### C++

C++ is a middle-level programming language developed by Bjarne Stroustrup starting in 1979 at Bell Labs

### Cloud

Cloud computing is a type of Internet-based computing that provides shared computer processing resources and data to computers and other devices on demand. It is a model for enabling ubiquitous, on-demand access to a shared pool of configurable computing resources, which can be rapidly provisioned and released with minimal management effort.

### Commutative (Abelian) Group

- Group
- ⟨S,∗⟩ is commutative if ∗ is commutative
- a ∗ b = b ∗ a for all a, b ∈ S

### Complexity Theory

- Provide mechanisms for classifying computational problems
- according to the resources needed to solve them
- The classification should not depend on a particular computational model
- should measure the intrinsic difficulty of the problem
- The computational may include time, storage space, random bits, number of processors, etc.
- typically the main focus is time, and sometimes space

### Cryptanalysis

Mathematical science that deals with analysis of a cryptographic system in order to gain knowledge needed to break or circumvent the protection that the system is designed to provide

### Cryptographic System

Secure Cryptographic System

An adversary with specified capabilities is not able to break it

Unkeyed Crypto-systems