Quote from: AnonyMint on November 28, 2013, 12:27:40 PM

Quote from: tinytiger on November 28, 2013, 12:23:43 PM

Quote from: botolo86 on November 28, 2013, 06:26:21 AM

Quote from: megastacks on November 28, 2013, 05:43:22 AM

Could someone explain in layperson terms why it is not possible to figure out a key to solve all future hashes or blocks and create bitcoins at will?

Also, and I hope to be in topic, why do we need to try millions of hashes before finding the right one? Isn't there a way to create a mathematical way to just get the right hash on the first try?

If there is, nobody has found it yet (afawk). And there is a LOT of interest in cracking hashing algorithms because they are used in many sensitive applications. Quantum computing is one thing to keep an eye on though because quantum computers, who make use of the fact that electrons can be in several different states at the same time, for computing could be able to crack any hash within milliseconds. But then Bitcoin could move to other hashing algorithms that can not be cracked by quantum computers.

Older hashes have been broken. Typically the longer a hash is around, the more attacks on the hash are found. However, Bitcoin could change the hash in that case, so that really isn't a problem.

I am slightly mistaken. Without checkpoints that prevent a longer chain from going too far backwards in time, a broken SHA-256 could be a serious threat. However the community has many copies of the history, I think there have been some checkpoints, and I don't think many clients have an incentive to erase that history from the ledger.