A method of updating and distributing secret keys in a distributed network, wherein the network comprises a plurality of nodes (100.1 to 100.5) connected to a shared medium of the distributed network, wherein each node of the plurality of nodes (100.1 to 100.5) is member of at least one group of a plurality of groups (LG 1 - LG 5), wherein each group is associated with a secret group key (KLID1 - KLID5), wherein each node of the plurality of nodes (100.1 to 100.5) is configured to store only the one or more secret group keys (KLID1 - KLID5), of which it is member, the method comprising: a first node (100.1) of the plurality of nodes (100.1 to 100.5), generating (S305) an authenticated update key request, wherein the authenticated update key request comprises an indication of a membership, of which the first node is member; the first node (100.1), broadcasting (S110) the authenticated update key request on the shared medium of the distributed network; each remaining nodes (100.2 to 100.5) of the plurality of nodes (100.1 to 100.5), receiving (S310) the authenticated key update; each remaining nodes (100.2 to 100.5), performing (S118, S128, S315-S325) an authentication verification based on the authenticated key update request; each remaining nodes (100.2 to 100.5), matching (S325) the respective memberships with the indication of a membership of the first node comprised in the authenticated key update request; each remaining nodes (100.2 to 100.5), in case of at least a partial matching of memberships, generating (S120, S130, S150, S340) an authenticated update key request response, which comprises an indication of the membership of the respective remaining node; each remaining nodes (100.2 to 100.5), in case of a partial matching of memberships or a mismatch of the memberships, generating (S140, S160) an authenticated update key request and broadcasting (S140, S150) the authenticated update key request on the shared medium of the distributed network, wherein the authenticated update key request comprises an indication of a membership, of which the respective remaining node is member. a first node (100.1) of the plurality of nodes (100.1 to 100.5), generating (S305) an authenticated update key request, wherein the authenticated update key request comprises an indication of a membership, of which the first node is member; the first node (100.1), broadcasting (S110) the authenticated update key request on the shared medium of the distributed network; each remaining nodes (100.2 to 100.5) of the plurality of nodes (100.1 to 100.5), receiving (S310) the authenticated key update; each remaining nodes (100.2 to 100.5), performing (S118, S128, S315-S325) an authentication verification based on the authenticated key update request; each remaining nodes (100.2 to 100.5), matching (S325) the respective memberships with the indication of a membership of the first node comprised in the authenticated key update request; each remaining nodes (100.2 to 100.5), in case of at least a partial matching of memberships, generating (S120, S130, S150, S340) an authenticated update key request response, which comprises an indication of the membership of the respective remaining node; each remaining nodes (100.2 to 100.5), in case of a partial matching of memberships or a mismatch of the memberships, generating (S140, S160) an authenticated update key request and broadcasting (S140, S150) the authenticated update key request on the shared medium of the distributed network, wherein the authenticated update key request comprises an indication of a membership, of which the respective remaining node is member. <EOS>