Quantum cryptography is a branch of cryptography that uses quantum mechanics to secure communications. Quantum cryptography has the potential to provide unbreakable encryption, by using the properties of quantum particles to detect eavesdropping attempts. Popular quantum cryptography platforms include QKD systems from ID Quantique, Toshiba, and QuintessenceLabs. Join our community A version control system (VCS) is a software tool that helps developers manage changes to source code over time. VCSs allow developers to track changes, collaborate with others, and revert to previous versions of code. Examples of VCSs include Git and Subversion.