What info do you have for me on quantum computing and bitcoin risk?
#asknostr
Discussion
8 years ago, I attended a cryptocurrency panel organized by Swiss investors. There, they mentioned that mining would become easier and faster with quantum computers, which would lead to more Bitcoin entering the market and its price decreasing. Everyone would be able to own Bitcoin more easily. It didn’t seem like a big risk to me.
I am concerned about the sha265 encryption being brute forced
cryptanalytic attacks are more likely.
Do you have any extra reads? I have a new bitcoiner expressing concerns
https://en.m.wikipedia.org/wiki/Grover%27s_algorithm
Grover’s algorithm is currently the best known algorithm for attacking *symmetric/one-way* cryptosystems using QC. It reduces the bit-security by half, so SHA256 would have 128 bit security, which is good.
Flaws in the hash, like a bias, are more likely to be abused (cryptanalysis).
You are my favourite cat
Same. It's relief that we didn't reach the quantum supremacy yet.
Quantum computing has not been demonstrated to do anything useful, let alone crack simple encryption.
The encryption Bitcoin is using is more advanced than a majority of the encryption used by corporations and general infrastructure.
If QC ends up being useful, and useful for cracking encryption, we will see other applications cracked before Bitcoin is at risk.
I don't remember who first explained this to me, but once I saw it I didn't worry about it again.
Not a cryptography expert but did a little digging. My understanding is that quantum computers (QCs) are a different type of computer that can perform new types of computations, not some super computer that does the same types of computations faster.
As discovered by Peter Shor in 1994, quantum computers will be able to calculate our private keys from our public keys. Has to do with the prime numbers we use in the crypto math. But QCs won’t be able to mine blocks quicker or reorg the chain. Hashes are mostly safe.
Bitcoin network will need to fork in a new type of key and signing algorithm so users can protect their funds, with enough time for all existing holders to transfer funds to new keys.
IMO notable concerns include:
1. What do we do with old or lost coins (like satoshi’s). Do we make them unspendable or let the first QC that can crack those keys become super wealthy?
2. Quantum safe crypto signatures are much larger signatures than our current sigs. When we upgrade the signatures we won’t be able to fit as many transactions in a block. Do we increase the block size to fit the same amount of txs or essentially accept a block size reduction?
3. How far away is the threat? When should we act? 5 years? 10? 50? Some argue we have plenty of time to learn more and weigh our options, others feel we should act now. Haven’t seen anyone agree on this one.