Threshold scheme enabled symmetric key member deletion

A method comprising:

• securing, by a managing node, communication in a network of a plurality of member nodes including a first member node, wherein communication is secured using a (k, n1) secret sharing scheme during a first phase, “k” is a first threshold of shares required to resolve a first key used in the first phase, and “n1” is a first total number of shares for the first key;
• announcing, by the managing node, a phase shift to a subsequent phase relative to the first phase;
• securing, by the managing node, communication in the network during the subsequent phase using a (k+x, n2) secret sharing scheme wherein:
• “x” is at least 1, and k+x is a second threshold of shares required to resolve a second key used in the subsequent phase,
• “n2” is a second total number of shares for the second key,
• each of the plurality of member nodes is previously in possession of exactly one corresponding unique share for the second key, and
• the first member node is previously in possession of a first unique share for the second key;
• and
• deleting, by the managing node, the first member node from the subsequent phase by broadcasting the first unique share for the second key and, if previously deleted nodes were previously deleted from the network, also broadcasting additional unique shares for the second key belonging to all previously deleted nodes.