Clipper Chip

The Clipper Chip was an encryption chipset proposed by the U.S. government in 1993 that implemented the Skipjack cipher with a built-in key escrow mechanism: law enforcement could decrypt any conversation by retrieving one half of the device's unique key from the National Security Agency and the other half from NIST. The proposal collapsed under technical criticism — a backdoor accessible to the government is a backdoor accessible to anyone who compromises the escrow system — and market pressure, as strong encryption without escrow became commercially dominant. The Clipper Chip remains the canonical example of how institutional attempts to preserve surveillance capability collide with the mathematical reality that a vulnerability is a vulnerability regardless of who holds the key. Its failure seeded the broader cryptography wars and energized the cypherpunk movement to develop censorship-resistant cryptographic tools.