Cryptography - Public Key Authentication (Certificate-based, Sender Verification)
Table of Contents
About
With the public key scheme, the Authentication is based on digital signature where the digital signature verification proves that a message came from a particular sender.
Type
There is two type of authentication:
- public key authentication based where the server authorizes only messages that can be decrypted by a authorized public key
- cert-based authentication where the server authorizes only client that are in possession of certificate signed by authorized CA.
See also:
Concept
Key
- the private key remains (only) with the user (The possession of this key is proof of the user's identity. Only a user in possession of a private key that corresponds to the public key located at the server will be able to authenticate successfully.
- the public keys are stored on the server in a file known as the SSH - Authorized Keys file (on Server)
For the procedure. see Digital signature procedure
Key Manager
The KeyManager is a program (or function) that decides which authentication credentials should be sent to the remote host for authentication during SSL handshake.
Type
Mutual
- Mutual Authentication, in addition to server authentication, the client also has to present its certificate to the server.
- The server verifies it
- If both server and client authenticated themselves, then authentication is a success.
See the dedicated page: What is a certification base authentication (also known as Client certification / Mutual TLS authentication) ?