Browse Prior Art Database

Cryptographic Message Terminal

IP.com Disclosure Number: IPCOM000089910D
Original Publication Date: 1968-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Bastian, M: AUTHOR [+2]

Abstract

Typewriters, equipped with two magnetic tape stations together with an encrypting device and a device for transmission over telephone lines are used as a cryptographic message terminal. Each tape is associated with a buffer register able to store the 7 or 8 code bits of a character. Reading and writing operations are made character-by-character and are controlled by a magnetic tape control unit. A character read out from a register can be typed or read into another tape through an associated register or transmitted to another station. A character read into a register emanates either from the tape associated with this register or from the local keyboard or from another register or from another station.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 60% of the total text.

Page 1 of 2

Cryptographic Message Terminal

Typewriters, equipped with two magnetic tape stations together with an encrypting device and a device for transmission over telephone lines are used as a cryptographic message terminal. Each tape is associated with a buffer register able to store the 7 or 8 code bits of a character. Reading and writing operations are made character-by-character and are controlled by a magnetic tape control unit. A character read out from a register can be typed or read into another tape through an associated register or transmitted to another station. A character read into a register emanates either from the tape associated with this register or from the local keyboard or from another register or from another station. The encrypting device, shown in dotted lines, is composed of a modulo-2 adder, without carry, and a register 3, a buffer for one character.

At the emitting station, the noncoded message to be sent is stored in a tape,
i.e., tape 1, and the ciphering key is stored in the other tape. A character of tape 1 is read into register 1, then a character of tape 2 is read into register 2. The contents of these two registers are added modulo-2 and the result, appearing in register 3, is sent to the telephone line. At the receiving station the incoming ciphered message is read into a register, i.e., register 1, and the ciphering key, the same as the one used in the emitting station, and stored in tape 2 is read into register 2 in synchronism with...