Bitcoin Forum

Hello,

I read that if sha-256 was compromised at some point in the future, or for any other reason, then bitcoin could switch to a different algorithm

can someone detail how exactly that would work, and what the implications to existing blocks would be?

from my understanding, everything is hashed with sha-256, then another algorithm would be incompatible with all previous blocks....


can someone elaborate on this?


if bitcoin, or any cryptocurrency, switched algorithms, what would happen to people's current addresses and the ledger of transactions? In theory it should be very simple for major pools to switch to the new client, as has been done numerous times in cryptocurrency land, but I've never seen it done with a different algorithm.

one of many many threads on the topic. use the search on the right side.
http://bitcointalk.org/index.php?topic=182331.0

sorry, thanks

edit: actually just because I mentioned quantum computers, this thread isn't about that. this thread is about the implications of switching the algorithm on an existing blockchain

np,yw   :)

actually this isn't about quantum computers, and the sticky thread didn't help. there are other reasons I can think of to switch algorithms

The short answer is that a QC cannot crack Bitcoin. One may be able to after Centuries, crack one address. Of course, that presumes that the coins don't move before then. If we ever have a computer that powerful, then cracking Bitcoin will be a very low priority task for such a device.

this thread isn't about quantum computers, there are other reasons that the collective may seek to change the algorithm of bitcoin or any other cryptocurrency.

this thread is about implications

While the protocol cannot be changed, the encryption can be. Any hard fork will recognise old coins as long as they include the old transactions in the blockchain. If they are moved, they must use the new fork. How the new hashes are generated has nothing to do with how the old ones were made.

thanks!

The encryption is part of the protocol. What you probably mean to say is that the hashing algorithm used by the protocol could be changed by core developer/mining consensus for a good reason, whereas changing the economic properties is far less likely to reach a consensus.

Yeah. The block rewards, the ten minute verify etc. will not likely be changed, but the hashing would probably be allowed. Maybe in a hundred years or so.