Method and system for issuing and using derived credentials

A controller for improving access security of a host server accessed by a mobile device, comprising:

• a communication interface for using a communication network;
• a storage for storing
• a kibble of a private key of derived credentials, the kibble mapping to a first group of non-contiguous bits in the private key of derived credentials to permit recovery of the private key of derived credentials via a bit-wise OR operation on the kibble and another kibble mapping to a second group of non-contiguous bits in the private key of derived credentials, and
• a proof of knowledge;
• and
• a processor configured to:
• (a) receive a proof of knowledge from the mobile device via the communication network,
• (b) check whether the received proof of knowledge matches the stored proof of knowledge,
• (c) when a match occurs, send the kibble to the mobile device via the communication network,
• (d) when a match does not occur:
• (1) check whether the access attempts threshold has been reached by the access attempts counter,
• (2) when the access attempts threshold has been reached, send a message to the mobile device via the communication network denying access, and
• (3) when the access attempts threshold has not been reached, send a message to the mobile device via the communication network inviting sending of a new proof of knowledge.

A mobile device for using a controller to improve access security to a host server, comprising:

• a communication interface for using a communication network;
• a storage for storing
• a first kibble of a private key of derived credentials;
• a processor configured to:
• (i) send to the controller via the communication network, a proof of knowledge based on a password received from a user,
• (ii) receive from the controller via the communication network, a second kibble of the private key of derived credentials,
• (iii) use the received second kibble and the stored first kibble to recover a private key of the derived credentials by performing a bit-wise OR operation on the received kibble and the stored kibble based on a mapping of the received kibble and the stored kibble to respective groups of non-contiguous bits in the private key of derived credentials, and
• (iv) send a derived credentials security certificate to the host server via the communication network.

A method of operating a controller, comprising:

• storing a kibble of a private key of derived credentials, the stored kibble mapping to a first group of non-contiguous bits in the private key of derived credentials to permit recovery of the private key of derived credentials via a bit-wise OR operation on the kibble and another kibble mapping to a second group of non-contiguous bits in the private key of derived credentials;
• receiving a proof of knowledge from a mobile device via a communication network;
• checking whether the received proof of knowledge matches a stored proof of knowledge;
• and
• when a match occurs, sending the stored kibble to the mobile device via the communication network,
• when a match does not occur:
• (1) checking whether the access attempts threshold has been reached by the access attempts counter,
• (2) when the access attempts threshold has been reached, sending a message to the mobile device via the communication network denying access, and
• (3) when the access attempts threshold has not been reached, sending a message to the mobile device via the communication network inviting sending of a new proof of knowledge.