DE3514660A1 - Electronic closing system having several locks and keys - Google Patents

Abstract

The system is constructed as follows: in all locks and all keys, a system-specific code (basic code G) is stored; in addition, the lock memories (s1) also contain the respective lock numbers (nj) and the lock memories (S1, S2) contain the lock numbers (nj) for which the keys are to fit in each case. To save storage space in keys to which a multiplicity of locks is allocated, the numbers of fitting locks are combined as far as possible to form ranges of successive numbers and only the range limits are stored. The lock memories (S1, S2) suitably also contain a priority and key number (Pi, Ni) in each case, and the lock memories in each case contain corresponding priority numbers (pi); the lock microprocessors are programmed in such a manner that a key only fits when the following holds true: Pi = pi or pi + 1 (Pi is the priority number stored in the ith key, and pi is the priority number stored at the lock side for this key), and when in the case Pi = pi + 1 pi is incremented by one unit with the initial insertion. A lost key can thus be rendered invalid without converting the associated locks; the spare key only needs to receive a priority number which is higher by one unit. The main field of application: large ... Original abstract incomplete. <IMAGE>

Description

Electronic locking system with several locks and

Keys.

The invention relates to a locking system according to the preamble of claim 1. Such a device with hierarchically ordered key and lock parts is described in European laid-open specification 98437.

In certain cases, for example for hotels, residential complexes or Operations building, you need a locking system that, in addition to individual keys for each lock also has group keys that open a number of locks and one Contains the appropriate master key for all locks in the system. Such hierarchies have usually been implemented purely mechanically up to now. Had to a number of disadvantages must be accepted: The system offers a limited Diversity and is relatively easy to copy; the areas that have a group key opens, cannot be changed easily; lost keys can only be done with a certain amount of effort - the cylinders of the associated locks must be replaced - invalidate.

That is why one had already thought of it, at least some of these Eliminate weak points through the use of modern electronics. So in the cited publication discusses a locking system, its parts when plugged together communicate with each other according to the following scheme: On one from the key The lock generates a random number x and transmits this number the key. Both parts convert x into a according to a given algorithm Intermediate size y and take a fragment from this size according to a certain rule y, which is the shorter the deeper fer the key or the lock are in the hierarchy. The y calculated on the key side is given to the lock and compared there with the variable y determined on the lock side; if they match the lock is then operated. Alternatively, provide different keys Although fragments y are of the same length, they work according to different algorithms; accordingly, the locks each contain the algorithms of all approved ones Key and check whether one of their algorithms matches the key algorithm matches or not.

Both concepts have their specific advantages, but they do not in any case the requirements to be placed on them. So is the first variant only limited flexibility, a fact that is particularly important when large Objects with frequently changing and / or complicated key-lock assignments are to be supplied. In the second variant, the locks must have a row of (reprogrammable stored) program parts and consequently regularly be equipped with relatively expensive program memories. In addition, in both cases, that changes in the key-lock assignment interfere with the electronics of the locks concerned, especially in the case of extensive building complexes can only be carried out with considerable expenditure of time and personnel.

The invention is based on the object of an electronic key-lock system of the type mentioned above so that you can choose a freely selectable key for each key and, if necessary, also assign easily changeable selections from the system's locks can. To solve this problem, a system with the features of claim 1 suggested.

In the proposed system, the basic code is used to distinguish of the individual systems is chosen so long that identification by unauthorized persons practically is excluded; typical code lengths are 24 bits or 32 bit. All programmable read-only memories are suitable as code memories such as PROMs, EPROMs, or EEPROMs; the security requirements are not too high (Example: vehicle locking system), diode or conductor matrices can also be used (cf. the earlier patent application P 3409611.6).

The requirement for a free choice of locks for every key is strict to meet, a yes / no decision must be possible for each lock in the system be, that is, save one bit per lock in the key. Because of the space required, such individual coding is only available for small and medium-sized ones Systems make sense. For very large objects with more than 104 logically distinguishable Locks are recommended instead - at least for keys with a large one Number of assigned locks - a specific group coding: one grabs the numbers of the locks to be blocked by the keys in blocks the following numbers together, with the exception of individual locks.

Then it is sufficient to separate the valid and invalid number ranges from one another to delimit, i.e. only to save the block boundaries. These limits are freely selectable; only the number of borders and thus the individual areas is through the capacity of the memory module is limited. This technique offers when the numbers were initially allocated sensibly, regularly sufficient freedom of choice.

A system according to the invention can be carried out with a relatively small Expand program storage capacity in such a way that a lost key made invalid without modification of the locks assigned to it and easily by one changed duplicate key can be replaced.

For this purpose, a key-specific number is added to each key as well as a priority number and a priority number for each lock for each lock matching Key saved. It is agreed that a key a lock can only operate if the key-side priority number is the same is large or one unit larger than the priority number stored for him in the lock, and that in the last-mentioned case the lock-side priority number for the first assembly The lock and key are automatically matched to the key-side priority number will. If a key is lost, a new key is now stored in the key center made out, which differs from the previous one only in that the priority number is increased by one unit.

All locks that operate from the lost key also fit its successor and can be relieved of the replaced key - and, if applicable, from its predecessors - no longer block as soon as the new key is received has been used for the first time.

If sub-key of the system (1, single key11), for example the room key of a hotel can be copied, so the inventive System can be designed particularly cost-effectively.

It is sufficient if the individual key is just a block with a stored Basic code and possibly

Carry key and priority number and the lock microprocessors - parallel to the data transfer routine for group keys - a program section to read out the memory data of the passive individual key.

Further advantageous refinements and developments of the invention are subject to additional claims.

The proposed system will now be based on an exemplary embodiment will be explained in more detail in connection with the accompanying drawing. Show it: Fig. 1 an allocation table between the individual keys and locks in the system, 2a to 2c the coding system of the keys and locks and FIG. 3 the dialogue between key and lock after putting them together.

The first step in designing a particular locking system consists in the logically distinguishable locks and keys as columns and to enter lines of a matrix and assign them to each other. Fig. 1 shows the beginning such an assignment table in which the keys are numbered consecutively row by row one below the other and the locks with consecutive numbers in columns are entered side by side. A mark on a matrix interface ("X" in the diagonal and "+" outside the diagonal) means that the key of the cut row should match the lock of the cut column. Of the The table shows that there are hardly any single keys in the strict sense and that the assignments scatter in such a way that they do not fall into a clearly structured hierarchy have it brought.

Figures 2a to 2c show what information in the individual System parts are stored. A key that only has a few locks (example: Single room and front door), contains a data memory S1 in which a 24-bit basic code G, a priority number Pi and a key number Ni are stored are. Such a memory could be, for example, that of the Siemens company under The EEPROM offered under the designation SDA 2116 K function, the 128 bytes with a Width of 8 bits each. The basic code consumes a maximum of this memory 6 bytes, so there is still enough space for storing the priority and key number remain. Furthermore, the individual keys each have a microprocessor C, for example the CMOS type 80 C 482 from Siemens in a micropack version (Fig.2a).

Contains a key to be used with a wide variety of locks next to the EEPROM, in which the basic code and key number are stored, and the Microprocessor yet another memory module S2 (Fig. 2b), for example the same type as block S2, in which numbers n of the matching locks as well the priority and key number are stored. (That in both building blocks the Key number is included, is only used on one key only related memories are combined with each other.) The block S2 contains the lock numbers in the form of area boundaries and individual lock numbers. Should be about a group key for all locks with numbers within the ranges 456 to 731 (Block) 953 to 3428 (block) 4263 to 4263 (single key) 6538 to 7325 (block) 8120 to 8120 (single key) and 8735 to 9249 (block) are only the digits 456, 731; 953, 3428; 6538, 7325; 8735, 9249; 4263 and 8120 stored.

One to two bytes are required for each digit, i.e. for each limit. With a A capacity of 1 kByte can be used for systems with up to 65,000 locks and 500 limits so define 250 valid areas. This allows a very free design of the hierarchical system with a large reserve for subsequent changes. Are expect many individual keys compared to larger blocks, one might Save some memory space by looking after the coding of the areas - in the mentioned Example between the digits 9249 and 4263 - put a separator mark. All further Numbers are then not used as area limits, but as individual lock numbers interpreted and therefore do not need to be stored twice.

The locks have two memories s1, s2 and a microprocessor c. In addition to the basic code G, the memory s1 contains a lock number nj; the memory s2, which should have an EEPROM with a storage capacity of 1/2 k bytes a priority number pi for each of the assigned keys (FIG. 2c).

So that the keys cannot be brought in, the from The opening code given to the lock cannot be copied. Done accordingly when putting the key and lock together - via contacts, IR signals or the like. - a data transfer in both directions, i.e. in dialogue.

In Figure 3 it is shown how this interaction takes place. First, the key and lock in their microprocessors form bC and rc, respectively a random number Z, z and transmit these numbers to the respective partner.

Each partner then encrypts his basic code G, g with the help of a mathematical function F, f, which contains the transmitted random number, to a random parameter K, k and sends this size back to the other partner. Each of the two partners then checks whether the parameter is received contained basic code matches its own. If this is the case on both sides, this is how the lock sends its number.

If this is valid, the key sends the opening code O to the lock, along with its key and priority number. Are these two numbers too valid, the lock generates an electrical pulse I, which is used to open a Activation or engagement of a clutch leads.

The basic code check in the other partner can be done mathematically perform in two ways: Either the other partner calculates - this alternative is known - the encryption with the help of its original information automatically and compares the encrypted Results with each other. Or the original information contained in the received size is transmitted through Recalculation gained and compared with the own original information. The corresponding Programming the microprocessor has no special requirements; the same also applies to the other program parts (transfer routines, dialog control, etc.). For further details, reference is made to the European patent application already cited referenced.

Should be in the course of the dialogue - for example when using a non-system Key - if a discrepancy occurs, the dialogue breaks off immediately. For one This means that unauthorized users do not obtain any usable data.

If a correct data exchange is intercepted, then only with knowledge of the program data can be obtained via a computer analysis. The data of the dialog are otherwise encrypted so that the code sent once is used for the next Opening is no longer valid.

The invention is not only based on the illustrated embodiment limited. In order to increase the security, one could use even more encryption operate; for example, the lock, key and priority numbers make it unrecognizable by means of a function from the random numbers and the basic code and / or the basic code stored in the system parts in a part-specific Way to disguise. When moving from active to passive keys, the cryptographic measures that were previously part of the) szC program in tables be relocated for memory programming, in particular to prevent the key from an unauthorized user to a higher hierarchy level is set. That being said, it can also be recommended once, with universal To work building blocks, for example with microprocessors, across systems are programmed, or save with a lock, the basic codes of several systems contain. It must be left to the expert in which way he required Saves data in the individual system parts; usually is key-sided a second memory module will only be required if the key for a large number of locks should fit. In addition, there is also the organization There is still considerable room for maneuver in terms of data exchange: That's enough, if the security requirements are somewhat lower if only the lock is a random number from sends, with the help of which then the key from its basic code one from the lock verified parameter forms. Such a simplified dialog offers in particular the possibility of using battery-free keys. Furthermore, each partner could transmit only small fragments of information in one go, both of which Alternate partners in certain ways. If this is a transfer too For comparison purposes, the first sign of inequality can help canceled, i.e. before any essential information is leaked out.

Finally, under certain circumstances it can also be expedient that instead of storing the matching lock numbers on the key side of each lock contains the numbers of the assigned keys, the key in the dialog his Number transmitted and the lock carries out the number comparison. This principle where the final decision is made by the lock is particularly safe because the Allocation memory in the lock is relatively well protected against manipulation.

13 claims 3 figures - blank page -

Claims (13)

Claims 0, <Electronic locking system with several locks and several keys matching at least one of these locks, whereby a) each Lock and each key has a memory (sol, S1), b) at least each lock has a microprocessor (} in) and c) lock and key when plugging together interact via electrical impulses, d a (i u r c h g e k e n n z e i c h e t that d) the memory of each lock and each key (s1, S1) contains a system-specific code (basic code G), e) that the memory of each lock (sol) contains a lock-specific number (lock number ni) and f) the memory each key (S1) contains the numbers of the locks that match it. 2. System according to claim 1, d a d u r c h marked ei c h n e t that the basic code (G) contains at least 20 bits and is especially 24 bits or 32 bits long. 3. System according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t that to store the appropriate lock numbers (nj) in the memory of a a specific bit is assigned to each key (S1) to each lock of the system. 4. System according to claim 1 or 2, d a d u r c h g e k e n n z e i c h n e t that for storing the matching lock numbers (nj) at least in the Save those keys that are supposed to fit more than 103 locks Boundaries of areas made up of consecutive numbers of matching locks (nj) and consist of at least one number (A- and multi-lock areas) are stored. 5. System according to claim 4, d a d u r c h marked e i c h n e t that in a first memory part the boundaries of the multi-lock areas and in a second, from the first memory part separated by a separator mark the boundaries of the included areas are stored. 6. System according to one of claims 1 to 5, thereby g e k e n n z E i c h n e t that the basic code (G) and the lock number (n) at least for those Keys that fit a maximum of five and, in particular, a maximum of two locks are stored in a single block (S1). 7. System according to one of claims 1 to 6, characterized in that g e k e n n z e i c h n e t that the memory of each key (S1) also has one Priority number (Pi) and a key-specific number (key number Ni) contains that the memory of each lock (s1) for each of the matching key numbers (Ni) also contains a priority number (Pi) and that a key is a lock can only operate if its priority number (Pi) is the same or around a Unit is greater than the priority number stored in the lock for its key number (p). 8. System according to claim 7, d a d u r c h marked e i c h n e t that when the priority number of a key (Pi) is one unit higher as the priority number (Pi) stored in the lock for his key number, the lock-side priority number when the key is put together for the first time and lock is increased by one unit. 9. Locking system according to one of claims 1 to 8, in which at least also those keys that for at least three and especially at least five Castles should fit (11group key11), have a microprocessor (C), thereby g There is no evidence that when the key is put together in the microprocessors and the lock (C or bc) each have a random number (Z, z) formed and the respective Partner is transmitted that each of the partners uses his basic code (G, g) a mathematical function (F, f) that contains the transmitted random number (z, Z), encrypted to a random-like parameter (K, k) and this parameter to the other partner sends back that each of the two partners checks whether the in the received parameter (K, k) contained basic code (G, g) matches his own and that if and only if this is the case on both sides and, if necessary, all others Tests are positive, the key sends an opening code (0), which then, if this code has been checked positively on the lock side, an actuation of the lock triggers. 10. System according to claim 9, d a d u r c h marked e i c h n e t that if the keys each have a key and priority number (fi or Pi), with the opening code (0) also the key and priority number (Ni or Pi) of the key and in the lock with the one there for the key stored priority number (Pi) is compared, the lock only upon receipt a valid priority number (Pi) is activated. 11. System according to one of claims 1 to 10, characterized t that at least those keys that are for at most three and in particular at most two locks should fit ("single key"), do not contain a microprocessor and the microprocessors of the respective matching locks (c) each have a program section have the key data when the lock and key are put together reads out. 12. System according to one of claims 1 to 10, characterized in that g e k e n n shows that the basic code (G) and the key are stored in encrypted form and locks each have a microprocessor (C, fc) which has the basic code (G) decrypted again before further processing. 13. System according to claim 9 or 10, d a d u r c h ge e n n z ei c h ne t that the lock numbers (nj) and possibly also the key and priority numbers (Ni or Pi) before being transmitted with a function that is derived from the basic code (G) and in particular also depends on the generated random numbers (Z, z), encrypted will.