Please never ever ever implement a Merkle tree as you did in https://github.com/jbenet/random-ideas/issues/20 . This is vulnerable to the same trivial collision attack as the original Gnutella THEX proposal.

EDIT: also, please implement non-power-of-2 leaf node Merkle trees as power-of-2 lead node trees with the rightmost leaves containing the hashes of the zero length array, that way the final block along with its hash chain to the root provides a cryptographic proof of file length. This prevents denial-of-service mischief where a malicious server claims a given resource is terabytes large and a poorly written client starts allocating TB of disk space on a filesystem that doesn't support sparse files.

Or, more efficiently, at each level of the tree where there are an odd number of nodes, add another leaf node containing the empty byte array on the right side of the tree to make an even number of nodes.

> Git is the single largest influence on me. After that, various other papers (all the CAN literature, bitcoin/bittorrent, CRDTs, etc), and conversations with people. in particular, two close friends (jzim, davidad).

Oh, interesting.

Funny coincidence: I actually met davidad once, when I first starting out at my job. I think because of his asynchronous logic automata. We somehow ended up discussing busy beaver Turing machines over ice cream†.

† Toscanini's near MIT, fantastic ice cream.

davidad is one of my favorite people in the world :)

> Toscanini's near MIT, fantastic ice cream.

Much agreed.