Plasma Cash: Plasma with much less per-user data checking


This is very interesting. Is it possible to put this “# of time spent” into the UTXO itself (avoid having a separate tree and increase the block header size)? Meaning the output of the signed tx now is an object.

[blknum1, txindex1, oindex1, sig1,       # Input 1
 blknum2, txindex2, oindex2, sig2,       # Input 2
 newowner1, denom1, #spent1 +1           # Output 1
 newowner2, denom2, #spent2 +1           # Output 2


Ah yes, that might be better. Then the snark can prove that # of times spent is nondecreasing.

Plasma cash doesn’t have the two inputs and two outputs scheme you pasted, though.


True, but still, I think it’s possible to have leaves in Plasma Tx Tree as an object with affiliated fields . I haven’t thought it through, but possibly we could put a { historical owners => # tx } object for each output. And a possibility from this is when this coin is being exited, root chain will charge historical owners for the number of tx being done on this coin. So that you could imagine over time, as more coin being exited, the tx will be eventually paid out. (assuming constant tx fee for each tx.)



Hello Dan.

After the last Plasma call I really liked your idea of “Plasma Debit” with quasi-channels user <-> owner. I work on the More Viable Plasma in parallel, but do you want to join some forces to make a “debit” prototype? The most interesting problem I see there right now is how to supply initial “empty” coins, so a user can get one and be able to accept the payment. One option is just deposit a full one and “split” it to “completely full” and “completely empty”, but I’d like to about splitting operation entirely and leave only transactions of A <-> operator <-> B type.

Sincerely, Alex


Hello everyone. I want to get a better understanding of the proof used in Plasma. I have a very basic understanding of cryptographic proofs at the moment.

Do any of you know of good resources that can help me catch up to the cryptographic proof conversation?

Thank you.


What proof are you referring to?