Embodiments described herein provide a tree-based key management protocol with enhanced computational and bandwidth efficiency. A tree structure including a plurality of nodes is formulated according to modules in a vehicle. A group key and a blinded key are computed for a leaf node from the plurality of nodes based at least in part on a multiplication operation defined in an ecliptic curve group. Or a group key and a blinded key are recursively computed for a non-leaf node based at least in part on a key derivation function and the multiplication operation involving a group key and a blinded key corresponding to nodes that is one level down to the non-leaf node.