Is there any site where I can use view key to check the balance of the wallet? I guess I can use the simplewallet for that, but is there any site for it? Or any other solution?
I don't think view key lets you see balance, actually, only received amounts.
It does work for cold storage.
Alternately, if you can account for spends another way, you can then subtract them, giving a balance. This is a bit tricky to do correctly since change will be scanned by the view key, so you have to subtract the payment amount
plus the change amount on any spends.
Yea. I am looking some way to check the balance of my cold storage, paper wallet. Would be great if the view key gave balance directly without need for user to do any calculations. But it is possible also that way.
But is there any site for that? Or have I to use some wallet software?
If you only want to confirm receipt of funds from one or a few transactions (and you know the IDs for those transactions), you could use
http://xmr.llcoins.net/checktx.html.
yeah im trying to wrap my head around why the viewkey / spendkey can't be used to scan for which output has been used as an input in a view-only mode. I know I've read it explained before, but I think it was on the order of "well the viewkey shows you what outputs are yours, and the spendkey lets you spend those outputs" . I mean I get part of the problem - having the spendkey does allow you to spend that output, so hence making a viewonly wallet with just the viewkey.
would it be possible (somehow) to hash the spendkey, and then somehow scan the blockchain with a hashed-spendkey... but then you'd need to somehow extract from each transaction... the term i want to use eventually is dehash, and I know thats unpossible (indeed the whole purpose of the whole thing).
So I guess really the solution would be a 3rd key?
What was the new enable-tracking or whatever I saw in the simplewallet. didn't I just recently ask this? i need more sleep.
No, that, uh, won't work.
What does work is creating key images for every output discovered by the view key scan. Of course this requires bringing your paper/cold wallet at least to a running state (can be an offline computer).
There is no (merged) simplewallet stuff for this yet. It'd be something like "watch-friendly"; store-tx-info is not related at all.
