Russian MK-85C "ANCRYPT" Crypto Device

MK-85C   © Andrew Davie
(source: Museum Of Soviet Calculators)

The MK-85C was a secret portable cryptographic device used mainly by the Russian military. Information has recently surfaced and was published on Andrew Davie's Museum Of Soviet Calculators.

The MK-85C is a modification of the MK-85 CMOS BASIC calculator, developed by the Russian firm ANCORT. The text for ciphering is entered from the alphanumeric keyboard and can be edited on a 10 digit display. The device has a key space of 10¹⁰⁰ and the device and encrypts in both numeric and alphanumeric mode.

More details on the MK-85C and a story of its use at an archived version of the Ancort website.  Andrew's web pages on Soviet Calculators contains a remarkable collection of old and more recent Russian build machines. Most interesting!

More cipher machines at Cipher Machines and Cryptology, where you also find a Cipher Machines Timeline.

Update: Andrew's pages are no longer available, and his links now redirect to preserved copies at the Internet Archive. Christos military and intelligence corner has an interesting book presentation about "Encryptors and Radio Intelligence. Shield and Sword of Information World" by Anatoly Klepov, the President of ANCORT. The Book's cover shows the MK-85C.