DE2457027B2 - PROCEDURE FOR PROGRAMMING ARRANGEMENTS FOR GENERATING RANDOM BINARY STRINGS - Google Patents

Description

Random binary strings are used in modern information technology for a variety of purposes used; z. B. as noise signals, as test signals for Clbertragungsstreckeu, as ciphertext for encryption of information.

For the latter use cases, random-like binary strings are extremely long period demanded, which with the help of a program at the same time, i.e. phase-locked on the broadcast and on the Let form the receiving place.

It is assumed that arrangements for the repeatable generation of random binary character strings are known to those interested in it. Is the period of such an arrangement The binary string supplied is extremely long, so in some cases only the Starting position result in a sufficiently high degree of security, and the starting position would be the key to be kept secret.

In some of the known methods, the starting position is established by a two-part process Key established with a basic key from time to time, the additional key for example before The beginning of the transmission of a new message is changed. So was z. B. in DT-AS 12 37 366 proposed the initial state of key pulse generators depending on the result of the To set a mixture of a first and a second piece of status information. This is the first status information Stored on the sending and receiving sides, the second is determined on the sending side and is unencrypted for the Receive side transmitted. The exemplary embodiment described in column 7 from line 45 and shown in FIG. 7 of a key pulse generator delivers a binary character sequence that is solely dependent on the initial state as Extract from a single possible binary string with a long period. In such a procedure similar status information leads to binary character strings that are similar to one another, which make it easier to decipher. The possible exclusion of a number of certain state information, which would result in binary strings that are similar to one another reduces the number of those that can be generated different binary strings and would be very cumbersome rules for creating the Require key.

In the previously known methods and circuits, the law for the formation of binary character strings is alone given by the rigid circuit structure.

The task leading to the invention was to find a method for programming arrangements indicate which random-like binary strings generate by which a plurality of each other independent binary strings can be provided to encrypt information.

The prerequisite for the changing application of different educational laws, the structure of the arrangement with several stages connected in parallel and / or in series, each stage being a randomly before a binary string of shorter period can supply, is in arrangements for generating random-like ones Extremely long period binary strings generally given.

The inventive method for programming multi-level arrangements which are repeatable Generate random-like binary strings using a base keyword and a The additional key word which changes occasionally is characterized in that the basic key word is decisive for the initial state of the individual levels of the arrangement, and that the additional key word in conjunction with the basic keyword one that Links within the individual levels and between the levels controlling education keys created.

The arrangement controlled by different formation keys is equivalent to a number of different ones Random generators, of which only ever one is used.

The basic keyword is known to everyone involved and can be set, for example, by means of a selector switch or from memories such as punched cards, punched strips or magnetic memories entered into the arrangement and by appointment from time to time to be changed.

The additional keyword can be transmitted in a known manner on the z. B. new for each message to be transmitted determined or generated by a random generator and transmitted unencrypted to the receiving end will.

As described, the additional keyword creates in connection with the basic keyword as an additional one Keyword an education key. For example, the individual characters of the additional keyword be decisive in determining which characters are taken from the basic keyword and become the education key can be compiled, or the formation key characters can be obtained through the logical combination of characters of the basic and additional keywords.

The individual stages of the arrangement generally contain multi-digit feedback shift registers or also multi-digit binary counters. Through the characters of the basic keyword, the individual Set the registers and the counter to a specific initial state before each transfer be set.

Through the characters of the education key you can

About logical circuits in the individual stages of the Arrangement can be controlled:

the limit addresses of the binary counters, the selection of the taps at the outputs of the Binary counter digits,

the selection of one of several inputs of each shift register,

the selection of one of several possible outputs of each shift register,

the selection of one of several possible taps on each shift register for a logic circuit in the feedback circuit leading signal,

the choice of logic circuit in the feedback network of the shift registers,
also inserted between the individual stages of the arrangement allocator circuits such. B. coupling matrices or multiple switches.

Claims (3)

Patent claims: 1. Method of programming multilevel arrays that are repeatable random-like Generate binary strings, using one basic keyword and one on a case-by-case basis changing additional key word, characterized in that the basic key word is decisive for the initial state of the individual levels of the arrangement, and that the additional key word In connection with the basic keyword, the links within the individual levels and between the levels are controlled Education key created 'S 2. The method according to claim 1, characterized in that that the characters of the additional keyword are decisive for the selection of individual, the Education key resulting in the sign of the basic key Iwrt it. zo 3. The method according to claim 1, characterized in that that the formation key characters were obtained through the logical combination of Characters dt-s Basic and additional keywords.