Incremental chain download using SPV proofs?

[grau]

What do you think of a protocol extension for SPV style chain download of the subset relevant for one's wallet?

A node would query SPV style proofs for transaction inputs relevant to it until proofs reach coin bases or verified by previous proofs.

[Mike Hearn]

Wallets don't need to know the dependencies of their own transactions, so I don't see why this would be useful.

[grau]

It would be useful for applications that care of the origin e.g. colored coins.

[Peter Todd]

Applications that care about origin, colored coins in particular, are already very SPV compatible; you're just looking at it from the wrong direction. What they could do is start with the genesis transactions and scan the chain forwards, rather than starting with a alleged colored coin and scanning backwards.