KSD-64
KSD-64 "Crypto-ignition keys" on display at the National Cryptologic Museum in 2005
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 kilo bits (65,536 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 as a fill device for transfer of key material, as for the initial seed key loading of an STU-III secure phone.
Newer systems, such as the Secure Terminal Equipment, use the Fortezza PC card as a security token instead of the KSD-64.