We extend TESLA in a number of ways to make it more efficient and practical. First, we present a new method to support immediate authentication, meaning that the receiver can authenticate packets as soon as they arrive.
Second, we propose optimizations concerning key chains. In particular, for applications that use multiple authentication chains with different disclosure delays, we present a new algorithm that reduces the communication overhead.
Finally, we give discussions on the time synchronization issues and derive a tight lower bound on the key disclosure delay, which makes the scheme much more practical. Next, we remove a scalability limitation of the simple time synchronization protocol. Furthermore, we discuss how a receiver can authenticate received packets even if it is not time synchronized at the moment in which it receives the packet.