Lost Bitcoins

[DeathAndTaxes]

Yeah that is nonsense.  2^256 is bigger than you think.  Not kinda bigger than you think asinenly bigger than you think.

If you converted the entire planet into a super computer and powered it by the sun you couldn't COUNT to 2^256 before the sun burned out, there isn't simply enough energy.  Of course that is doing something fantastical like building a perfect computer (one at which higher efficiency violates the laws of thermodynamics) and capturing the entire energy output of a star.   That isn't finding a collision that is just counting 1, 2, 3, 4, 5, 6, 7 .... 2^256.   

[werneo]

Yeah that is nonsense.  2^256 is bigger than you think.  Not kinda bigger than you think asinenly bigger than you think.

If you converted the entire planet into a super computer and powered it by the sun you couldn't COUNT to 2^256 before the sun burned out.  

Nothing is impossible if you have enough time, energy and processing power.

I am hesitant to send this argument further into absurdity.... but about 20 years ago mathematical physicist named Frank Tipler came up with a model for a computer that had infinite processing power, time and energy. His discovery may have cracked him up because he realized the computer could be "god" (or something like that). I won't speak to Tipler's religious beliefs, but the "Omega Point Theory" has been peer reviewed by Oxford professor/ quantum theorist David Deutsch: http://129.81.170.14/~tipler/physicist.html (see http://arxiv.org/find/all/1/all:+AND+David+Deutsch/0/1/0/all/0/1)
http://www.physics.ox.ac.uk/al/people/Deutsch.htm

In brief, Tipler's model says that it is possible for conscious beings to purposely engineer the collapse of the universe, and that the collapse can be balanced to produce infinite time and energy to be used for an infinite amount of information processing. In other words, this is a closed universe deriving energy from an infinite, organized collapse.

I think it might be possible to create an "Omega Point"-like quantum computer that can solve ANY crytographic puzzle with brute force time and processing power and that would be instantaneous from our point of view. 2^256 is doable if all you have is time and an unbreakable calculator. The Technological Singularity might be able to figure this out on its own.

http://129.81.170.14/~tipler/summary.html

Some of Tipler's peer-reviewed articles:

http://arxiv.org/find/all/1/all:+AND+Tipler+AND+Frank+J/0/1/0/all/0/1

The Ultimate Future of the Universe, Black Hole Event Horizons, Holography, and the Value of the Cosmological Constant
http://arxiv.org/abs/astro-ph/0104011

Closed Universes With Black Holes But No Event Horizons As a Solution to the Black Hole Information Problem
http://arxiv.org/abs/gr-qc/0003082

I'm on twitter all week... https://twitter.com/werneo

[odolvlobo]

Sorry, but with 100PHs network, you can easily "guess" a collision of sha-256, or guess a collision of a collision of a sha-256.

The bitcoin network is already at 10 PH/s, and you think that another power of 10 is all it takes to destroy SHA-256? Considering that it takes the 10 PH/s bitcoin network 10 minutes to guess just a 62-bit hash, how long would it take a 100 PH/s network to guess a 256-bit hash?

I can answer that:

25,108,406,941,546,723,055,343,157,692,830,665,664,409,421,777,856,138,051,584 minutes.

[werneo]

The next logical question is whether Lost Bitcoins are recoverable using quantum cryptography.

Quantum computers and Bitcoin
https://bitcointalk.org/index.php?topic=133425.0

Will bitcoin survive quantum computing?
http://www.reddit.com/r/Bitcoin/comments/1eodjq/

Bitcoin Is Not Quantum-Safe, And How We Can Fix It When Needed
http://bitcoinmagazine.com/6021/bitcoin-is-not-quantum-safe-and-how-we-can-fix/

Will quantum computing kill cryptography?
http://mathoverflow.net/questions/128176/will-quantum-computing-kill-cryptography

I haven't found a direct answer to the question so far.

[kjj]

The next logical question is whether Lost Bitcoins are recoverable using quantum cryptography.

...

I haven't found a direct answer to the question so far.

Seriously?  Despite the rumors, the search box here on the site is not used to send messages to Santa.  It searches the site, and if you had used it to search for "quantum", you'd find many of the dozens of posts that do answer this question directly.

[knightcoin]

lost is lost .. move fwd

[countryfree]

People regularly loose banknotes, some gold coins were in boats which sunk, and some diamonds have felt in a fire. There's nothing new with people losing BTC.

[tsoPANos]

People regularly loose banknotes, some gold coins were in boats which sunk, and some diamonds have felt in a fire. There's nothing new with people losing BTC.

But btc isn't like real gold or currency. The total amount of total bitcoins produced is fixed, wich means that btc will extinct in a matter of few minutes or a geological era.

[werneo]

This article by Chris Pacia answers my question comprehensively:

Bitcoin vs. The NSA’s Quantum Computer

Bitcoiners can rest easy because SHA-256 isn’t threatened by quantum computers (although that doesn’t mean someone won’t find a feasible attack in the future).

http://www.bitcoinnotbombs.com/bitcoin-vs-the-nsas-quantum-computer/

[tonychow]

According to current technology, there is no way to recover the lost bitcoins. Can quantum computing recover? As I know, using quantum to solve computing problem is still in preliminary research stage and we do not see big progress. The only promising area in quantum as I know is in to enhance the security. But if current encryption technology cannot survive, we will create a new one. Otherwise, not only bitcoin, there is nothing can encrypt.
To wrap it, do not worry about quantum.

[mestar]

According to current technology, there is no way to recover the lost bitcoins. Can quantum computing recover?

Oh boy.   

Sure, but quantum computing can recover them only if they are truly lost.  If the keys are hidden in a safe, there is nothing that quantum can do.  Truly magical that quantum thing.

[tonychow]

According to current technology, there is no way to recover the lost bitcoins. Can quantum computing recover?

Oh boy.   

Sure, but quantum computing can recover them only if they are truly lost.  If the keys are hidden in a safe, there is nothing that quantum can do.  Truly magical that quantum thing.

Lost means no one knows private key. Quantum computing is used to guess private key, no matter it is lost or not.

[aminorex]

Why does it seem like 99% of necro-posts are useless drivel based on idle speculation and fanciful imagination rather than well thought out logic based on facts and reality?

Because life without joy and imagination is scarcely living.  And because if you behave arrogantly everyone thinks you have a teeny-tiny wee-wee.

[DannyHamilton]

Why does it seem like 99% of necro-posts are useless drivel based on idle speculation and fanciful imagination rather than well thought out logic based on facts and reality?

Because life without joy and imagination is scarcely living.  And because if you behave arrogantly everyone thinks you have a teeny-tiny wee-wee.

Neither of those answer why necro-posts suffer from delusions at a significantly higher rate than non-necro-posts.

[Xav]

What if ....

Someone was a bit nonchalant and did not back up his/her coins, but ... But he/she remembers his/her private key. Is there a way to 'restore' these 'lost' coins? IOW, is there a way to match private key and a specific address in the block-chain?

[cr1776]

What if ....

Someone was a bit nonchalant and did not back up his/her coins, but ... But he/she remembers his/her private key. Is there a way to 'restore' these 'lost' coins? IOW, is there a way to match private key and a specific address in the block-chain?

If you know the private key, then you can access the coins:

https://en.bitcoin.it/wiki/Private_key

Just as if you wrote the key down or printed it.

[Mavrick]

SEND lost bitcoins here lol

[Wilhelm]

What if ....

Someone was a bit nonchalant and did not back up his/her coins, but ... But he/she remembers his/her private key. Is there a way to 'restore' these 'lost' coins? IOW, is there a way to match private key and a specific address in the block-chain?

As I understand it:

The Bitcoin address is a sha-256 hash of the public key.
The "private key" isn't really a private key but more a public/private keypair.

Yes you can easily extract a public key and bitcoin address from a private key.
Go to www.bitaddress.org and fill in a private key under the tab wallet details... it will give you the address.

[tonychow]

As I understand it:

The Bitcoin address is a sha-256 hash of the public key.
The "private key" isn't really a private key but more a public/private keypair.

Yes you can easily extract a public key and bitcoin address from a private key.
Go to www.bitaddress.org and fill in a private key under the tab wallet details... it will give you the address.

+1.

You are not keep the coin, but the private key in the wallet. The wallet software has a copy of your private key,
so it can send on behalf of you. If your computer is compromised, so does the wallet and your key.
The information on how many coin do you have is in the block chain. All the transaction history is there, and the
wallet calculate how many bitcoin you own based on that information.

[DannyHamilton]

As I understand it:

The Bitcoin address is a sha-256 hash of the public key.

The bitcoin address is a base58check encoded RIPEMD-160 hash of a SHA-256 hash of the public key.