Constant TOUCH_ID_SEALED_PASSWORD_MIN_LEN 

const TOUCH_ID_SEALED_PASSWORD_MIN_LEN: usize = _; // 93usize

Minimum encoded ciphertext payload: 65-byte P-256 X9.63 public key + 12-byte ChaChaPoly nonce + 16-byte tag.

The encrypted password itself may be empty, so 93 bytes is the true minimum.