System and method for secure communications based on locally stored values

A system for secure communication, the system comprising:

• a first node of a first security group of one or more security groups, the first security group having a first plurality of nodes each having a synchronized data set, the synchronized data set having a first seed value, the first node being configured to
• store a code number, the code number being one of a random or pseudorandom number;
• generate a master key based at least in part on the first seed value;
• generate a first cipher key at the first node using the master key and the code number;
• encrypt user data at the first node using the first cipher key;
• generate a first signature based on the user data;
• a second node of the first security group storing the synchronized data set and configured to,
• receive a start frame from the first node, the start frame including the code number, the encrypted user data, and the first signature at a first signature location in the start frame;
• generate a second master key equivalent to the first master key;
• generate the first cipher key using the second master key;
• decrypt the encrypted user data using the first cipher key;
• and
• verify the first signature in the received start frame.

A method for secure communication within a dynamic security group (DSG), the method comprising:

• storing, at a first node of a first DSG of one or more DSGs, a synchronized data set (SDS) having a first seed value and a member ID for each node of a first plurality of nodes associated with the first DSG;
• communicating securely with at least a second node of the first DSG using the SDS;
• receiving a nomination message at the first node from an authenticator node, the authenticator node being a communication node external to the first DSG, the nomination message indicating
• a request from a third node to the authenticator node to join the DSG, the third node being a candidate node outside the first DSG, and
• a validation of a second signature of the third node;
• performing, by the first node, a handshake with the third node based on the nomination message;
• transmitting, by the first node, a membership message to all members of the DSG indicating addition of the third node to the DSG;
• and
• updating the SDS of the first DSG with a member ID of the third node.

A method for secure communication within a dynamic security group (DSG), the DSG having a plurality of nodes, the method comprising:

• receiving, at an arbiter node, a nomination message from an authenticator node, the nomination message indicating a request from a candidate node to the authenticator node to join the DSG;
• performing, by the arbiter node, a handshake with the candidate node based on the nomination message;
• and
• transmitting a membership message to the plurality of nodes of the DSG indicating addition of the candidate node to the DSG, the membership message including an instruction to update a synchronize data set (SDS) for the DSG to include a member ID for the candidate node.