* The current rules for when an Activity Entered is accepted allow it to refer to an older activity than the last one. If echoing is disabled, two Activity Entered could be sent, each pointing at the most recent Activity Seen, and there would be no proof of the order of the two. Reordering the two might cause different results though. This is not only a problem when 2 developers are connected; it also lets a single developer produce a proof chain that is ambiguous about what order they entered 2 things. Fix: Make a Activity Entered have a pointer to the previous Activity Entered that was accepted, in addition to the existing pointer. Then when one developer sends two Activity Entered that don't echo, there's still proof of ordering. When two developers are typing at the same time, only one of their inputs will be accepted. The client should only consider an Activity Entered legal if it points to the last Activity Entered that the client saw. May as well make Activity Seen have a pointer to the last accepted Activity Entered as well. This will make it easier when supported multiple developers, as each time a developer gets an Activity Seen, they can update their state to use the Activity Entered that it points to. * Use protobuf for serialization, to make non-haskell implementations easier? * Leave the prevMessage out of Activity serialization to save BW. Do include it in the data that gets signed, so it can be recovered by trying each likely (recently seen) Activity as the prevMessage, and checking the signature. (If doing this, might as well switch to SHA512, since hash size does not matter.) * loadLog should verify the hashes (and signatures) in the log, and refuse to use logs that are not valid proofs of a session. (--replay and --graphvis need this; server's use of loadLog does not) Everything else in debug-me checks a session's proof as it goes. And, everything that saves a log file checks the proof as it goes, so perhaps this is not actually necessary? * Add a mode that, given a log file, displays what developer(s) gpg keys signed activity in the log file. For use when a developer did something wrong, to examine the proof of malfesence. * gpg key downloading, web of trust checking, prompting Alternatively, let debug-me be started with a gpg key, this way a project's website can instruct their users to "run debug-me --trust-gpg-key=whatever" * How to prevent abusing servers to store large quantities of data that are not legitimate debug-me logs, but are formatted like them? Perhaps add POW to the wire protocol? Capthca?