Detecting when a private key has been swept

[kezown]

Does anyone know how the Casascius Bitcoin Analyzer site knows when a coin is Active/Opened? I'm working on an idea that requires knowing when a private key has been swept by a mobile wallet.

Any info or resources that might be able to help me would be greatly appreciated.

[HeRetiK]

I guess the Casascius Bitcoin Analyzer site simply checks whether a Casascius address had an outgoing transaction.

Apart from that there's no way of knowing whether a private key has been swept because no such information is being tracked or held anywhere.

[TryNinja]

The above.

Keep in mind that anyone could unpeel the Casascius, get the private-key but don't sweep the coins immediately. The only thing that identifies whenever it was swept is an outgoing transaction (like HeRetiK said).

[kezown]

I guess the Casascius Bitcoin Analyzer site simply checks whether a Casascius address had an outgoing transaction.

Thanks for your reply.

This is what I need. How do I check if a specific address (that I know) had an outgoing transaction?

[ABCbits]

This is what I need. How do I check if a specific address (that I know) had an outgoing transaction?

There are few ways :
1. If you're running full node, add address as watch-only address. Then configure walletnotify to run script (https://bitcoin.stackexchange.com/questions/24457/how-do-i-use-walletnotify)
2. Use 3rd party API/service which notify when there's transaction related with specified address

[bigmaster23]

You can study programming and create a program that reads privatekey through your own program whether it was swept or not, also you can watch a btc address if it has an outgoing transaction by doing some website crawling and parsing.

[keychainX]

I guess the Casascius Bitcoin Analyzer site simply checks whether a Casascius address had an outgoing transaction.

Thanks for your reply.

This is what I need. How do I check if a specific address (that I know) had an outgoing transaction?

You need to build a block sniffer and create an sql database of all used keys, then updated the database for each mined blocks.

there are a few github repos, just use search, but most likely you could build your own, using python.

like this https://github.com/alext234/rpc-sniffer

you can also read more on this page
https://en.bitcoin.it/wiki/Raw_Transactions#listunspent_.5Bminconf.3D1.5D_.5Bmaxconf.3D999999.5D

Ideally you would set up your own full node with the full chain, run a block parser to create an preferably sql database of all txs and then update it whenever a new block is mined.

/KX