DE2101177A1 - CIRCUIT FOR ENCRYPTION DEVICES - Google Patents

Description

rcueruanwcnie

Dr.-lng. \ / Vi! Ielm rich!

Dipl-ing. Y / u ^ ang Heiciiei

6 Frankiuri a. M. 1

Paiksiraße 13 2101177

European trading company . Vaduz

(Liechtenstein)

Circuit for encryption devices

Encryption methods that are common today work in many cases in such a way that they come to a head for teletype operation are. This has the advantage that devices designed according to such a method are linked directly to the international telex network can be; or that at least the 5-hole tape, the one in the teleprinters ^ for? »Application comes as a link can serve between telecommunications network and encryption device.

Dual coding is used in the international telex network

used, whereby five elements come into play, which 2 = 32 different Results in combinations, the allocation of which in the CCITT- f Code No. 2 is set.

In most cases, encryption is carried out in such a way that a key generator of the type in which you e.g. in Swiss Patent 362 555, one key group is queried for each character group, and the two Information groups are mixed multiplicatively for each character element (exclusive-or operation). The following applies Rule:

LxL = L LxO = O OxL = O OxO = L

Sa / cfa - 1 - 22 497 a

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It can be seen that the results are in a 5-digit binary code again will include all 32 combinations.

In the international telex network, however, the group "0000 0" is normally not permitted. She will just post the respective agreements between the telecommunications organizations concerned. There is even a plan to do it once in general to be blocked in order to be able to use them for official signaling purposes.

The present invention now allows a mixing method of the type mentioned above to be carried out for encryption, wherein but achieved through targeted influencing of the key generator becomes that only 31 different combinations occur on the transmission path.

The circuit according to the invention will be explained in more detail, for example, with reference to FIGS. 1 and 2, FIG. 1 being a block diagram and FIG. 2 shows the detailed representation of an embodiment.

1 and 2, 1 denotes a key generator which encodes its information in a multi-digit format Dual code, in this case five digits, on s-contacts. With 2 eats a character detector and 5 denotes a Mixing stage, which is omitted in FIG. 2 for the sake of simplicity. With 6 a further character detector is indicated, while with 4 an input or primary memory and with 7 an output or secondary memory is designated. Depending on how the circuit is used, additional input and output means, not shown, are required. In the case of line operation, a so-called reception distributor (series-parallel converter) would be connected upstream of the input memory 4 and the output memory 7 a transmission distributor (parallel-series converter) downstream.

In the case of non-line-bound operation, the input memory 4 can be controlled, for example, by a keyboard, and the Output memory 7 gives its information on a punched tape

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Punch off. Mixed possibilities are also conceivable: ζ.Β. Input from keyboard and output on line or input from line and output on paper tape punch or printer (the all, also prints the technical CCITT signals!) Always be aware that CCITT code no. 2 or a code similar to this is used.

The key generator 1 is provided with a step generator 8 (Fig. 2) for each character to be processed by one work step advanced. For this purpose, the step generator 8 is activated by switching means 10, which are not described in greater detail, when they arrive of a character to be processed is triggered. For example, these switching means can be a keyboard contact that is activated on keyboard input is common to all keys.

The key information now offered by the generator 1 is determined by the position of the five contacts s ... .. .s,. <| The lower layer may correspond to the dual "L" and the upper to the "0".

The input of characters requires setting of the contacts a, ... e, through the input means, e.g. the keyboard. Here, too, the lower contact layer corresponds to an "L", the upper one to one "0". These contacts together form what is known as the primary memory 4, since they contain the primarily entered character information. mation is embodied.

If the contact n _{Q is closed} by the cam disk assigned to it, which is driven by a motor 9 on command of the switching means 10, then depending on the position of the contacts of the primary store 4 and the generator contacts s ,, ... S ₅ , pull up the relay coils F ... J, which together form the secondary memory 7, since they contain the information to be output from the mixer circuit.

A current flows, for example, from the + pole of a common current source (not shown) via relay G, s «. fo, no to the 0-pole. Is in each case in one of the forms that are formed in this way

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five parallel circuits one left or right contact in the opposite position than the other, so no current flows, and that Relay is not energized. We have to observe the linkage rule mentioned at the beginning, the four possibilities to two Offers results.

Each relay F ... J is assigned a self-holding contact f, ... j, in such a way that energized relays can continue to hold via these contacts via contact n, even if contact n ₃ opens. The secondary information is available at the contacts f ~ ... L · for a certain period of time. The switching means 10 initially started the motor 9, which runs through a cycle and drives the cam disks of the contacts n 1 and n 1, the closing times of which partially overlap.

After the secondary information has been sent from the secondary memory 7, the contact n opens, so that the five mentioned relays fall back into the rest position (= O-position).

Instead of the cam contacts, relay contacts or other control means are of course also conceivable, "all of them together with the step generator 8, per character to be processed run through a certain work cycle, which is as follows looks like:

1) Input of the character in the primary memory 4 and simultaneous Triggering of the device.

2) Provision of the key character by the generator 1.

3) Mixing and simultaneous input into the secondary memory "(controlled by contact n_ ).

4) Storage of the secondary character in the secondary memory 7 (controlled by contact n ₄ ).

5) Submission of the secondary character by the secondary memory 7.

6) Deletion of the secondary character (by contact n *).

The relays F ... J now carry a further set

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Contacts f ... j _2> which are combined in a chain circuit to form detector 6. It can be seen that the combination in which all five relays are in the rest position brings the relay coil K to the elevator. This is the combination "0 0 O 0 C or CCITT No. 32. The contact k actuated by the coil K now acts in the actuated state on the key generator in such a way that its contacts s .... '" Sc ₁ for this Make contact in the lower position (LLLLL), which corresponds to encryption without conversion, ie a clear transmission.

The contacts work in parallel to the contacts s .... .. .s ..

s, p ... Scp, connected to another chain, represent the detector; it can be seen that in the "LLLLL" position they bring the relay coil 0 to the elevator. The contact o assigned to the coil 0 acts in the actuated state on the generator 1 in such a way that it offers a different key symbol. For example, the step generator 8 can be made to let the generator 1 continue to run at rapid pace until a key combination is offered that is different from "L LLL L". Depending on the functional principle of this key generator, this can mean a more or less large number of steps. However, today's technology allows such circuits, for example on the basis of the already mentioned Swiss patent Ko. 362 555, in which the number of steps to be run through in the worst case can be determined in advance, from which the minimum necessary rapid step speed can be derived, since everything has to be done before the secondary character is stored.

It is clear that the position "LLLL L" of the contacts of the key generator, forced by contact k, has no effect on the pacer, because in series with contact o, the normally closed contact k _? is looped in, which in its actuated (open) position would prevent any rapid opening command.

It can be seen that due to the circuit described, of course, fully electronic, hydraulic, pneumatic

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or can be realized in still other ways, the following effects can be achieved;

1) The character combination "0000 0" never occurs on the primary side on. (This follows from the definition of the CCITT alphabet No.2, where this combination is blocked.)

2} The key generator 1 delivers as the product of its key series never voluntarily sends the information "LLLL L" to the mixer (if it appears once, the generator runs in Rush continues and is prompted to offer a different combination.)

»3) If the characters" 0000 0 "appear on the secondary side, this storage is prevented and instead the character offered on the primary side is cleared in the secondary memory entered. The key generator 1 then, and only then, inevitably supplies the combination "LLLL L".

Since the mixing takes place as such modulo 2, it can be seen that nothing else is necessary for decryption than repeated encryption with the same key character in each case. The decryption circuit therefore looks exactly the same as the encryption circuit described.

The substitution control on which this circuit is based driving for certain characters is now not limited to multi-digit aual coded characters. It is e.g. in a ternal system the following linkage rule is possible:

Clear signs 1 Key characters - 6 - Secret sign 1 0 L. 09840/1032 L. 2 L. L. J 3 J L. 0 4th 0 J J 5 L. J 0 6th J J L. 7th 0 0 0

Clear signs T 2101177 L. Key characters Secret sign 8th . J O L. 9 O J

Inversion L = J, inversion J = L, inversion O = O.

If the secret character is mixed with the inverted key character according to this linkage rule, the following applies Table shows the original clear sign again:

Secret orig. Inverted deciphered character key character key character plain character

1 L (L) J 0 -J

2 J- (L) J L

3 0 (L) J J

4 J (J) L 0

5 0 (J) L L

6 L (J) L J

8 L (0) 0 L

9 yrs (0) 0 yrs

This process corresponds to the decryption

It can be seen that the deciphering corresponds again to the original plain character according to the table shown.

It is now possible, with measures similar to those already described, to prevent, for example, the combination "0 0 0". or some other specific combination appears at the exit. Similar means for the key generator are also possible, which in turn ensure that a certain key character combination is never entered into the mixer stage.

The ternary link is of interest to key * devices that are provided with print output.

According to the international telegraph regulations

ORIGINAL INSPECTED

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encrypted messages only consist of groups of numbers or letters. So you can build key barley in a ternary three-digit code 3 «have 27 character combinations; 26 are assigned to the letters of the international alphabet, A combination, e.g. "0.0 0" is not used. It is encrypted according to the link rule mentioned with a three-digit. Ternary signal. From the above it is guaranteed that only the 26 letters appear at the exit!

Summary for ternary systems: The circuit must be designed in such a way that

1) the combination_ "0 0 0" for input of clear characters never appears (by simple cloning)

2) When the combination "0 0 0" appears on the key encoder, it continues to run or another combination offers

3) When the combination "0 0 0" appears at the output, encryption with ¹¹ O 0 0 "and inversion takes place, as shown in the following example:

Clear signs Key characters Secret sign 0 0 0 L. J 0 0 0 0

The secret sign is a blocked sign. The key generator must therefore generate a connection like follows:

Clear sign key sign secret sign 0 0 (+ inversion) 0 L 0 (+ inversion) J 0 0 (+ inversion) 0

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• The decryption brings the following sequence:

Secret sign Key characters Deehiffrat 0 O 0 J L. 0 O 0 O

It should be remembered that the inverted key signals are used for decryption. The Forbidden coordination "O 0 0", thus a clear connection (Key character "0 0 0") and perform inversion.

Secret sign Key sign Decipher A

0 O (+ inversion) 0

J 0 (+ inversion) L.

0 0 (+ inversion) O

The originally entered clarity appears again. chen.

A possible circuit for remote systems, like just one is shown in principle on Fig. 3, with only the following essential elements are shown:

a, b, c are the three primary storage contacts, which by definition can each occupy 3 layers.

s ,, S-, s "are three triple contacts of the not shown ^ j put key generator. ·

P, Q, R are polarized relays with a central contact position. They act as secondary storage in collaboration with theirs Holding contacts p, q, r and the cam contact n ..

^P 2 ' ^q 2 * ^r 2 ^are * ⁿ connected together in a chain, they represent the 000 detector of the secondary signal and in this position excite the relay KK, which on the generator (not shown) gives the command "code 000" and the 3 switches "INV "gives the command" invert ".

Finally, at p ₃ , q ₃ , r ₃ the secondary calibration is due.

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Those skilled in the art will readily understand the circuit structure explained above for a dual system Recognize the function according to FIG. 3 and can imagine the elements that are still necessary, not shown, since they are in principle are the same as there.

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Claims (1)

Claim: Circuit for encryption barley, the multi-digit coded signals from a first input point with multi-digit coded signals from a second input point in terms of character elements link, characterized in that at least one character detector is assigned to a key generator and when a first specific combination of characters (Hill) occurs at its exit, it influences it in such a way that it has a offers other character combination and that at least one character detector is arranged at the output of the circuit, which is at Occurrence of a second specific character combination (O 0 0 0 C) the key generator to deliver a specific, always the same Character combination (Hill) prompted before the exit captured, second specific character combination is released. - 11 109840/1032 Blank page