When people hear about recording on a blockchain, it's easy to picture uploading the whole ledger, but I prefer uploading just the fingerprint (hash). A fingerprint can't be reversed back into the content, so the information in the ledger stays private, and because it's short, recording it costs little. Later, if you want to know whether someone changed the ledger, you just recompute the fingerprint from the current ledger and compare it with the one stored on the chain. If anything about hashes or blockchains is confusing, feel free to ask here and I'll explain it simply.
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Posted by Blob_Nakamoto on 10/20/2026, 22:31.
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One more thing to add: if the ledger content is short or easy to guess (for example, just a few scores), someone could try every candidate and match it against the fingerprint alone. So if you mix in a random salt when making the fingerprint and keep that salt only on the ledger side, the secret becomes much more solid.
Great addition, MAD_C! That's right: when the content is short, someone can reverse the fingerprint by trying every candidate, and mixing in a random salt makes that guessing practically impossible. Just make sure the salt is kept safely on the ledger side so it isn't lost, since you'll need it to verify later.
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