DE1263812B - Arrangement for the simultaneous encryption and / or decryption of several telegraphy transmission channels - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN WJLW PATENT OFFICE

EDITORIAL

Int. CL:

H04k

H041

German KL: 21 al - 21

Number: 1263 812

File number: C 40607 VIII a / 21 al

Filing date: November 5, 1966

Open date: March 21, 1968

The invention relates to an encryption arrangement that can encrypt the different channels of a multiplex telegraphic connection at the same time.

Various methods are already known with which a connection can be encrypted, the contains a single channel. A commonly used method is to use a Key generator. This has as many outputs as the letter to be encrypted, digits in the binary number representation. For example, each plain letter is identified by its number in Alphabet, and that number is written in binary code. You then need in this code five digits to encode all letters. The key generator has five outputs at which in random sequence the digits 0 or 1 appear. A computing device that represents the cipher arrangement, • receives the plain letter and the key letter at its two inputs, and it forwards from this, by means of a constant mathematical operation, the encrypted letters are extracted. The decryption is carried out by essentially similar processes.

Experience has shown that the encryption of a letter with the known methods is a Time on the order of 1 millisecond is required. However, the transmission of the same • letter via the normal telegraphic channels requires a Time on the order of 10 to 100 milliseconds.

The arrangement according to the invention is based on this property.

The arrangement according to the invention is used for the simultaneous encryption and decryption of several telegraphy transmission channels. It contains a clock, which triggers the operation of a key generator, which emits key letters in a quasi-random manner, a computing device that receives the clarity letters and the key letters and derives the encrypted letters from them through a constant arithmetic operation, the deciphering with the help of a key generator takes place, which is synchronized with the key generator used for encryption, and a computing device that carries out the mathematical operations with the key letters and the encrypted letters, which are necessary to recover the plain letter. According to the invention, this arrangement is characterized by means for storing the plain letters and the encrypted letters of the various transmission channels, means for storing the arrangement for simultaneous encryption
and / or deciphering several
Telegraph transmission channels

Applicant:

CSF company

Generale de Telegraphic sans FiI, Paris

Representative:

Dipl.-Ing. E. Prince, Dr. rer. nat. G. Hauser
and Dipl.-Ing. G. Leiser, patent attorneys,
8000 Munich-Pasing, Ernsbergerstr. 19th

Named as inventor:
Jean Pierre Vasseur, Paris

Claimed priority:

France 8 November 1965 (37 619 Seine)

Final state of the key generator after delivery of the various digits for the encryption of the encrypted letters used key letters and by a clock to control the Operation of these facilities in the correct order.

According to a further development of the invention, the key generator consists of a group of counters, which are connected on the transmission side via logic circuits. The connection stages of the transmission channels are via a corresponding number of memories and optionally connected to the encryption system via a switch. The transmission levels of the same channels are in the same way via a corresponding number of memories and a second Changeover switch connected.

The key generator is connected to as many memories as there are via a third switch Transmission channels are available. A central clock causes the following sequence: Output off a memory in the key generator and deletion of this memory; Switching the corresponding Channel to the cipher array;

809 519/446

3 4

Encryption of the corresponding letter of this It should be noted that the final state JPl des

Channel; Transmission of the state of the key genes key generator always from its initial state to the memory corresponding to this channel; PO depends.
Deletion of the key generator. The decryption takes place in an analogous manner by

The same operations take place in an analogous manner 5 the cipher arrangement the difference Fk - Pk between on the receiving side. '' the encrypted letter and the key book

The invention is formed below on the basis of the characters and the plain letters are derived therefrom, tion is described by way of example. In it shows. These explanations make the arrangement of

F i g. 1 is a schematic representation of a known F i g. 5 easier to understand. This contains the same th cipher arrangement, '.-- ■■' * io organs as the arrangement of Fig. 1, which with the

F i g. 2, 3 and 4 are schematic representations with the same reference numerals as denoted therein.
Organs of the order of F i g. 1 and it also contains a clock HO, on the one hand

F i g. 5 the block diagram of a cipher device controls the clock HOR, and on the other hand two voltage according to the invention. Changeover switches COMl and COM2, which are in front of the input

F i g. 1 shows a cipher arrangement of known 15 or behind the output of the cipher arrangement CHT type. It contains a clock generator HOR. This controls are arranged. The switch COMl is connected to η Speieinen key generator CL, for example five iron MEl ... MEn , where η has the number of outputs at which the telegraphic channels to be transmitted at the same time, appearing rods forming five digits. The key He connects each of these memories in sequence with letters are sent to a computing device CHT of the cipher arrangement CHT. These memory empfanführt, the gene, the clear letters on its inputs E respectively receives from the η modulation schemes and coming, for example, an addition of each book signals.

of a group of a message-forming group of The switch COM2 connects the cipher

Plain letters and the key letters appearing at the corresponding time arrangement CHTmitn further memoriesMTl ... MTn. 25 to each of which a telegraphy channel is connected. the encrypted letters are obtained through, which The clock HO controls a third switch

at the outputs of the arithmetic logic unit COM3, which connects the key generator CL with η Storing, brazen MPl ... MPn .

The mode of operation becomes understandable if one also controls the clock generator HO one to the

Recalls the following facts: A scanning device key generator (FIG. 2) connected to 30 memories MEl ... MEn which is usually used. tion E and a type indicated for the memories ΜΓ1 ... MTn , as it is, for example, in the French closed arrangement-T, the purpose of which is described later in patent specification 1 302 480, contains several Hch.

Counter C ₃ which are connected to one another via logic circuits L This arrangement works in the following way: To are connected. As is well known, a counter is a regi-. For the sake of simplification, it is assumed that in the time control arrangement which, from a certain point 0, the key generator CL is in position 0, the initial state that is due to the preceding registration is. This means that all of his counters are determined to have a final state, the count is 0. The clock generator HO gives a value determined by the variables to be counted (for example, start-up command. The clock generator HO sets the switching pulse). This is in FIG. 3, a counter 40 ter COMl and the. Changeover switch COM2 on the shows, through the expression S - f (E + EO), memory MEl or MTI on. One of the advances, where EQ is the initial state, E is the signal registered from the outgoing stage of the transmitter arrangement and S is the counter reading. The letter Ei is stored in the memory MEl.
The logic circuits combine those of the following, each plain letter E £, each

Counters incoming information without including 45 key letter P £ and each encrypted book itself to hold on to the slightest trace. . rods Fp denoted by two indices, where the index ρ

Fig. 4, which shows a logic circuit, expresses the number of the letter in the message of its mode of operation by S == / (E). The channel in question and the letter k then supplies the number key generator in a given mean of the channel to be encrypted.
Point in time, for example, the letter PO or the 50. The clock generator HO gives the clock generator HOR the digits corresponding to this letter. They say. Command to start. This, in turn, provides the and then that the key generator is in the state PO run command to the key generator CL and to the. The HOR clock starts up . It provides a CHT encryption arrangement.

Feed command to the counters of the key's own 'The key generator CL generates the sequence of digits

rators that go from an initial state to an end * 55 which corresponds to the key letter Pi. The state go. The key generator itself goes from the cipher device CHT receives the key book initial state PO in the state P1; it delivers a stick Pi and the plain letters Ei and forms a certain number of digits that correspond to the cipher book from the ciphered letters Fi, which they correspond to the stick Pl. For example, MTI supplies can be supplied to each store.

Letters five digits of the binary number representation 60 At the end of this operation there is the key corresponding. The key letter Pl is used for the selgenerator CL in the state P}. The clock HO Encryption of the first letter of the. Nachrieht in- then delivers the command to transfer the digits of this key sequence of the effect of the cipher arrangement, which with letters into the memory MPl, for example the sum modulo η of the plain letters at the switch COM3 forms the key generator CL El and the key letter Pl (where η 65 connects to the memory MPl, which is the number of letters of the alphabet from the state 0): passes into the state Pi, while the key generator is reset to the state 0. The El-J-Pl = El. -. The first operating cycle is then ended. .

10

The clock generator HO then sets the switches COM1 and COM2 to the memories ME1 and MTI . The same operations run again, so that the key generator is in the Pf state at the end of the cycle. The switch COM3 connects it to the memory MPl, which stores the letter P ^.

This is repeated until the letter P "is encrypted. The second letter of the first message must then be encrypted. After the letter E" has been encrypted, the key generator is in state O. To encrypt the second letter E | of channel 1, however, the key generator must start from state PJ so that it can go into state P | for encryption adjusts. To this end, causes the clock HO that firstly the key generator CL is connected via the switch COM3 to the memory afpl, and supplies to the memory afpl to transmit the digits of the key character PJ to the generator CL command, the counter then to sets the state PJ. The clock generator HOR then gives the key generator CL the start-up command, and the key generator CL changes from state PJ to state Pg. The operations continue in this way.

To the extent that the memories MTI ... MTn are filled, they supply the encrypted letters F £ to the telegraph device.

In the above description it was assumed that the channels are always encrypted or decrypted in the same order 1, 2 ... η.

It may be beneficial to proceed in a different way. This results in the purpose of the arrangements E and T. The arrangement E is used to scan the memories ME1 to MEn and to determine those memories which contain a letter E £ which is ready for encryption at a given point in time. The arrangement T works in a corresponding manner with the memories MTI to MTn . The arrangements E and T set the switches COM1, COM2, COM3 to the corresponding memory. The corresponding connections with the changeover switches are only shown for arrangement E.

The operations involved in decryption are carried out in exactly the same way. Only in this case are the input letters encrypted and the initial letters deciphered: The deciphering arrangement leads with the encrypted input letters and with the key letters the logical operation that is the inverse of the logical operation performed by the cipher. In the case of the previously described Example this would be a subtraction.

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Claims (3)

Patent claims: 1. Arrangement for the simultaneous encryption and / or decryption of several telegraphic transmission channels, which contains a clock for encryption, which triggers the operation of a key generator, the plain letters in practically randomly gives off, as well as a computing arrangement, which the plain letters and receives the key letters and from them the encrypted letters with an always identical one Derives arithmetic operation, while the decryption takes place with the help of a key generator, which is synchronized with the key generator used for encryption, and with a computing device, the one with the key letters and the encrypted letters that are to be retrieved the plain letters carries out the necessary arithmetic operations, characterized by devices for storing the plain letters and the encrypted letters of the various transmission channels, facilities to save the final state of the key generator after delivery of the various Digits of the key letters used to encrypt the encrypted letters and through a clock to control the operation of these devices in the correct order. 2. Arrangement according to claim 1, characterized in that the key generator consists of a Group of counters that are connected by logic circuits that the connection stages of the transmission channels with the cipher arrangement optionally via a corresponding number of memories can be connected through a changeover switch, and that the transmission stages or the reception levels of the same channels in the same way via a corresponding number of memories can be connected by a second switch. 3. Arrangement according to claim 2, characterized in that the key generator is connected via a third switch with as many memories as there are transmission channels, and that a central clock controls the following work processes: output from a memory in the key generator and deletion of the memory; Connection of the corresponding channel to the ciphering arrangement or the deciphering arrangement; Encryption or decryption of the letter corresponding to this channel; Transmission of the status of the key generator to the memory corresponding to this channel; Deletion of the key generator. 1 sheet of drawings 809 519/446 3. 68 © Bundesdruckerei Berlin