Chain of trust
An important part of collaborative efforts during the development of a project is ensuring the quality of its code. This includes protection against the accidental corruption of the repository, and also from malicious intent—a task that the version control system can help with. Git needs to ensure trust in the repository contents: both your own and other developers’ (especially trust in the canonical repository of the project).
Content-addressed storage
In Chapter 4, Exploring Project History, in the SHA-1 and the shortened SHA-1 identifier section, we learned that Git currently uses SHA-1 hashes as a native identifier of commit objects (which represent revisions of the project and form the project’s history). This mechanism makes it possible to generate commit identifiers in a distributed way, taking a cryptographic hash of the commit object. This hash is then used to link to the previous commit (to the parent commit or commits).
Moreover...
