DE1066610B - Security device for mixing devices in the case of encryption processes - Google Patents

Description

kl. 21a ¹ 21

INTERNAT. KL. H 04 fc

PATENT OFFICE

A "

L28513VIIIa / 21a ¹

REGISTRATION DATE: SEPTEMBER 5, 1957

NOTICE
LOGIN
AND ISSUE OF THE
EDITORIAL: OCTOBER 8, 1959

. In the known methods of encrypting messages, which are transmitted according to the principle of telegraphing multiple alphabets, the principles of modern telex technology are used, and a plain text is generally mixed with a ciphertext and sent to the receiving end using the same ciphertext correctly to generate plain text again. In order to store this cipher text, it is known to store the same on recording media. You can therefore prepare the cipher text in the form of a so-called punched tape and convert it into electrical current images using the discharge device of an automatic transmitter, which are then mixed with the electrical current images of the plain text.

Devices have been proposed in which a receiving system receives the clear message and a sending system sends out the encrypted message. The device is constructed in such a way that the above-mentioned receiving system is also suitable for receiving the encrypted message, and that the transmitting device on the receiving side sends out the clear message after decryption. Since with this arrangement the first incoming start step must be used to clarify immediately whether the following characters come from the remote side, i.e. in the encrypted state, or from the own, i.e. the local side, - the quality of the telex characters deteriorates , especially the starting step. In order to avoid this, an apparatus using two receiving systems has been proposed. Here, one system is used to only record the clear message for the purpose of subsequent encryption, while the other system is only used to record the encrypted message for subsequent decryption. '

In the devices proposed so far, the electrical and mechanical structure are carried out in such a way that encryption and decryption are possible, but no consideration has been given to security against unintentional transmission of the plain text. It can therefore happen that, for example, the plain text that comes into the key or mixer device and is mixed with a key strip is still sent out as plain text or as mirrored text if, for example, the keyhole strip tears or is not transported or if the power supply to the Key or mixing device fails completely or briefly, so that the device switches itself back from the mixed state to the clear state. It is also desirable that the subscriber, the security facility for mixing equipment
in the case of encryption processes

Addendum to patent 1,019,695

Applicant:

Standard electrical system Lorenz

Corporation,

Stuttgart-Zuffenhausen,

Hellmuth-Hirth-Str. 42

Walter Fischer, Pforzheim,
has been named as the inventor

receives a message, can get rid of it if he receives garbled characters. This mutilation can take place, for example, in that the key strip is inserted the wrong way round at one or the other point of the subscribers communicating with one another, or because the key strips are automatically offset during the mixing process. It is also desirable that the subscriber who receives a message correctly can get rid of this reception if he himself wants to send a much more urgent message in between. Measures have already been taken for this purpose in normal telex correspondence, namely when the sending station has a punched tape transmitter in which a so-called counterwriting device is installed. Since in the mixing device, especially in the one described above with two separate receiving systems, the telegraph circuit in one receiving system and the circuit of the sending device in the other receiving system is completed, there is a direct influence according to the method that has been used up to now in the usual teletype traffic, not possible. In order not to change the existing punched tape transmitters and teleprinter devices and still meet the above conditions, it is proposed in the main patent to arrange a counter-write relay in the transmission circuit in series with the encryption device, which brings a relay into effect when the receiving subscriber counter-writes, that the encryption device is stopped by switching off the motor via another relay. Besides, that will

: ■■; ·. ... 909,637 / $ 16

Mixer beam countersign automatically from »Encrypt« state switched to »Clear« state. This ensures that immediately afterwards the two participants communicate with the counter letter in plain text and any who may have occurred Can eliminate defects, d. i.e. not only that the sending mixing device, but also the mixing device of the counter-writer automatically into the Can be switched back to the "Clear" state.

de-energized, drops out and disconnects the teleprinting device from the remote line through the contact 12 in a single-pole manner. By opening contact 11, the circuit of relays 1 and 2 is interrupted. By closing the contact 13, the signaling device 3 comes into effect. The drop-out delay relay 2 closes the long-distance line through contact 21 after about 150 msec. By pressing key 6, relays 1 and 2 respond again, SO ¹

In the Jlaurjtpatent the device is made so that if 5 comes back to the long-distance line 7, 8 that the line power line is opened, until the teletype 5 sends, the contact is made

Remote switching device disconnects the connection. Is open at- 52, whereby the relay 2 drops out and for the For example, however, no malfunction interrupting the connection closes the contact 21 in preparation. Remote switching device is available, a control device in the remote control

If the opening time is correct (e.g. from 2 to 3 p.m., the writing instrument is switched on for a short time), as already mentioned, 3 seconds) of the long-distance line unencrypted text the contact 51 is opened, so that the relay 1 drops out, on the pipeline. But since in general the through its contact 12 it closes on the pre-eventual occurring faults through control-prepared contact 21 the long-distance line. If any of the directions are displayed, the operating control equipment in the teleprinter is during personal on the partially or completely disturbed .20 of the transmission becomes effective, the connection remains Teletype operation attentive. held via the long-distance line and is single

The invention is based on the idea that short-circuited at borrowed. The signaling device is switched on via the contact 13 of the smaller, quickly to be rectified faults in the remote relay 1. Leave the write connection in place so that the traffic can continue after the fault has been eliminated 25
can. It is therefore proposed according to the invention
that disturbances of the teletype operation act on switching means that short-circuit the trunk line and
the teleprinter at least one pole from the
Disconnect the capillary. The advantage of the invention is 30
that the long-distance connection remains in place in any case, and that the transmitter is at least unipolar
is separated from the long-distance line, neither can any
Message to be sent out.

In the embodiment of the invention, it is expedient to open the long-distance line on the part of the receiving subscriber in the event of disturbances before the short circuit for the duration of a telegraph character / to influence the counter write relay of the transmitter. i | Here, as soon as the teleprinter is disconnected from the long-distance line, a signaling device indicating this state is activated.

The teleprinter is connected to the long-distance line by means of an operating button. With this control button is used to switch from »encrypt« to »clear« at the same time switched.

An embodiment of the invention is explained in more detail with reference to the drawing].

7 and 8 denote the pipeline that goes through the Contact 21 is closed. The high-voltage connection 9 and 10 is controlled by the remote switchgear. Immediately the relay 1 can pick up and closes the contact 11 (self-holding contact) and switches with its contact 12 the long-distance line to the teleprinter 5. The delayed pick-up relay 4 makes the contact

41 to, thus lifting the bridging of the contact 11, switches the relay 2 on and prepares the signaling device 3 by closing the contact

42 before. The relay 2 opens the contact 21. If one of the built-in teleprinters 5 speaks Control devices on briefly, the contact 51 is opened. This will make the relay!

Claims (5)

Patent claims: 1. Security circuit · for mixing devices with encryption methods in which the key stored on a recording medium is mixed with the encrypted or to be encrypted message, with two identical ones. Receiving systems according to Patent 1 019 695, characterized in that disturbances in the telex operation act on switching means (1, 2) which short-circuit the long-distance line (7, 8) and separate the teleprinter (5) from the long-distance line at least one pole. 2. Safety circuit according to claim 1, characterized in that the long-distance line on the part of the receiving subscriber in the event of malfunctions before short-circuiting for the duration a telegraph sign is opened. 3. Safety circuit according to claim 1 and 2, characterized by a. in the event of a malfunction Effect of the incoming relay (1), which disconnects the long-distance line and another with a delay Acting relay (2), which short-circuits the long-distance line. 4. Safety circuit according to claim 3, characterized in that the separation of the teleprinter from the long-distance line is indicated by a signaling device (3). 5. Safety circuit according to claim 3, characterized in that a button (6) is provided when operated after the teleprinter has been disconnected from the long-distance line this is connected to the trunk line and at the same time the encryption device from the state »Encrypt« is switched to the state »Clear«. Documents considered: German Auslegeschrift No. 1 001 314. 1 sheet of drawings © 909 637/169 9.59