A method of mutual verification between a client and a server is disclosed. The method comprises receiving a request via a telecommunication link, the request comprising an address of the server; receiving a verification data; decrypting the verification data with a private key of the server; identifying an account identity (ID) of the client from the decrypted verification data; generating a first logon token; generating a logon message comprising the first logon token and a uniform resource locator (URL) of the server; encrypting the logon message with a public key of the client; transmitting the logon message via the telecommunication link; receiving a logon request comprising the account ID and a second logon token; and determining whether the second logon token matches the first logon token.