Vault-grade matrix lock. Requires the exact passphrase to open — no partial matches accepted.

Tamper-evident chamber. If the casing has been altered since sealing, it will refuse to open.

Repeating keyword lattice — a hand-cipher construction. Letters only; punctuation and spacing pass through untouched.

Rolling combination dial. The offset value is the key — set it before turning the handle.

Foreign-script compression casing. No key required — the shape of the characters is the lock.

Zigzag rail mechanism. Nothing is substituted — the same pieces of evidence are simply rearranged along the number of rails set.

Grid-based letter-pairing lattice, built from a keyword. Works two letters at a time — a filler letter may appear where a pair repeats.

Coordinate grid mapping. No key required — every letter is recorded as a pair of numbers marking its position on the tablet.

Mirror-letter substitution. No key required — the mechanism reverses itself, so the same action seals and unseals.

Pulse-signal encoding. No key required — every letter becomes a short burst of long and short pulses.

Plain-text repacking. No key required — the evidence isn't hidden, just repacked into a denser block.