I just read bitcoinJ's working with contracts tutorial and I am puzzled as:
it seems to me that n-m addresses are implemented in Bitcoinj using plain multisig (as defined in this bit of the developer's guide, and discussed here)
I looked for implementations of addresses controlled by more than one private key with pybitcointools (tutorial on that here) and on libbitcoin's wiki. It seems to me that these two libraries use P2SH.
Most libraries seem to use P2SH, but bitcoinJ chose the other way it seems (or is it?)...
In an implementation of micropayment channel with bitcoinJ on one side and, say, libbitcoin on the other ; will the two sides be able to interoperate?
(edit: I m talking here only about unidirectional payment channels)