Cerberus FTP Server Professional edition can perform public key authentication for SFTP connections. When using public key authentication, Cerberus will verify that the signature presented by an SFTP client matches the public key associated with that user.
How Public Key Authentication Works
The Cerberus FTP Server User Manager allows each user to be configured with a required authentication method. The authentication method can be set to require either a password only (the default), a public key only, or both a password and a public key for authentication. There is also an option for selecting a public key file when the authentication method for a user is set to public key or password and public key authentication. The public key file can be in SSH format (as defined in RFC 4716), OpenSSH v2 format, or from a PEM or DER encoded certificate.
Multiple SSH Keys per Authenticated User
A single user can authenticate with more than one different SSH client key. This allows interactive or automated processes that share a common username and sign-on from several different machines to enjoy the benefits of multi-factor authentication without the hassle of key replication and coordination.
Take a look at the help documentation for more information on how to configure a user for SSH public key authentication.