dotConnect for PostgreSQL support OpenSSH or IETF SECSH key files. You may use such utilities as 'ssh-keygen.exe' or 'puttygen.exe' for generation of the corresponding public/private key pair.
For example, the IETF SECSH can have the followink look:
---- BEGIN SSH2 PUBLIC KEY ---- Comment: "rsa-key-20090722" AAAAB3NzaC1yc2EAAAABJQAAAIEAjidZERzyvAUjQqOSCA2H5BWOKAamB2qgb0/f ak35AKnqvcuOeiJyqlmqz7/49oKa6T6+EjXp+pMbzTK0+YIn9Kg88jjnHJHA4D7s cGN7TQ6mY/dhht7VmkdTVVn5orbmnyTroZq2Ruj4Vus9xl57DFCdZFTnMMO4ruHL x+9PFHU= ---- END SSH2 PUBLIC KEY ----