Basically, GreenAddressIt will send a transaction with nLockTime whenever someone makes a deposit. This transaction sends the funds back to the depositor. The nLockTime transaction effectively acts as a deposit expiry: after this time, it will be included in a block and the depositer will get the funds back.
Oh, ok. That makes sense. Almost anyway.
Not sure where the funds get sent to in this transaction. There doesn't appear to be any setting for a return address.
Also not sure why you need to run special code to redeem the transaction. Guessing this might be somehow related to the previous point, in the previous paragraph.
GreenAddressIt works by using multi-factor transactions. Both the user and GreenAddressIt must sign for a transaction to be made from deposited funds. This allows the recipient to disregard the possibility of a double spend since GreenAddressIt has to authorize a double spend, which it won't do if the site is honest. To prevent a database loss or owner disappearance from destroying the funds, the nLockTime transactions are made returning funds to the depositor's address.
Looks like GreenAddress is going to provide the option for enforced spending limits and delayed payments in the future. Interesting.
So all outgoing transactions from GreenAddress get signed by two signatures, right? If so, what is this "Instant Confirmation" checkbox for when making outgoing transactions?
Also assuming that GreenAddress must keep copies of both private keys, the passphrase looks to short to have an encoded private key, and yet that appears to be all I require to gain access to my account. If so, am a bit unclear how this is any better then having them hold just one private key.
Thanks