Privacy is selective disclosure not secrecy

The cypherpunk tradition that shaped bitcoin distinguishes privacy from secrecy: a private matter is something one doesn't want the whole world to know, a secret matter is something one doesn't want anybody to know, and privacy is "the power to selectively reveal oneself to the world" (Eric Hughes, "A Cypherpunk's Manifesto," 1993, as quoted in Decrypting Money). On this framing, bitcoin's design — a fully public transaction ledger paired with pseudonymous addresses rather than named accounts — is an attempt at selective disclosure rather than concealment: anyone can verify the ledger, while identity attaches to an address only if its holder reveals it.

Nuance: the framing describes a design intent, not a guaranteed property. The same book's notes concede the counterweights: bitcoin offers pseudonymity rather than anonymity (its privacy is compared unfavorably to physical cash in the book's own Figure 5.2), address reuse degrades it, and "tainted coin" labeling shows that a transparent ledger lets third parties draw distinctions between coins — pressuring fungibility, the very trait the selective-disclosure model depends on. Whether bitcoin as actually used delivers Hughes-style selective disclosure, or merely delayed disclosure against well-resourced chain observers, is a live debate the definitional distinction does not settle.

Common misstatements: "Bitcoin is anonymous" (it is pseudonymous; the ledger is public forever). "Privacy advocates want secrecy" (the manifesto's point is the opposite — selective revelation, not universal concealment). "The public ledger means bitcoin has no privacy model" (it has one — pseudonymity plus fresh addresses — the dispute is about how robust it is in practice).