

BTProof – Trusted timestamping on the Bitcoin blockchain - danboarder
https://www.btproof.com/

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314
Seems like a bad idea: adding wealth destruction to a currency that is
deflationary by design. It is also unnecessary.

Take 2 addresses that you control. Send not one transaction between them, but
inside a sequence. Say you want to encode a 512-bit hash, split it into 29-bit
chunks. Encode each chunk as the low-order bits of the transaction value so
each transaction may cost up to 1BTC.

Send each transaction from address-1 to address-2 and then back to address-1
(no net change in balance).

Treat the entire sequence as an encoding of a hash (looping transactions
between addresses with values under 1BTC).

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kang
Why cant we simply hash the document to create a key and then use this key to
seed and generate an address?

    
    
        var bytes = Crypto.SHA256(key, { asBytes: true });
        var btcKey = new Bitcoin.ECKey(bytes);
    

We can then send some money to this address and back.

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jsprogrammer
Then anyone who gets the document, gets the key?

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icebraining
So what? Worst case scenario, the attacker gets control of the BTC before the
user can recover them, but that's no worse than the original proposal, where
the value would always be lost

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jsprogrammer
Well, how could you prove that you were the one that inserted the value into
the blockchain? If anyone can have the key, anyone could have inserted it.

~~~
kang
We are talking timestamping here.

If any money was ever sent to the address generated by the hash of the doc,
even if the current balance at that address is zero, proves that that document
existed at the time money was sent. Why care about ownership?

