Posts tagged #Proof-of-work
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Bitcoin and quantum computing
A quantum computer will not be able to rewrite Bitcoin's ledger: it will probably be able, one day, to open some of its locks. What Shor's and Grover's algorithms actually do, why elliptic curve signatures are the target and hashes are not, which coins already have their public key in view (about 35% of the circulating supply, recounted on our own node) and which do not, where the machines stand with dates attached, where the post-quantum migrations under discussion stand (BIP-360, BIP-361), and why the hard part is not technical but a matter of governance: what to do with the coins of those who can no longer move them. A snapshot declared as of July 2026.
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The prisoners meet the generals
Getting strangers who do not trust each other to agree on a single truth, with no arbiter and over an unreliable channel: that is the Byzantine generals problem, the heart of distributed consensus. Classical solutions hold only among known, counted participants; Bitcoin solves it on an open network with proof-of-work, which makes lying expensive and turns the generals into a defused prisoner's dilemma. Out of it also comes a time chain: a chain with a direction, which fixes the order of events. The value lies there, in the problem solved.