The KSD-64[A] Crypto Ignition Key (CIK) is an NSA-developed EEPROM chip packed in a plastic case that looks like a toy key. The model number is due to its storage capacity — 64 Kib (65536 bits), enough to store multiple encryption keys. Most frequently it is used in key-splitting applications: either the encryption device or the KSD-64 alone is worthless, but together they can be used to make encrypted connections. Less often, it is used alone for transfer of key material, as for the initial seed key loading of an STU-III secure phone.
