The secrets of the intercom key. Which will open any door?Door keys are in the pocket of everybody. Understand how they work and can be demagnetized, and is there one key for all doors.

Types of keys for intercoms

There are several families of syrups.

1. “Pills”. Officially the standard is called “Touch memory” (TM) or iButton is the key contact in the housing MicroCAN. In “the pill” uses a 1-Wire Protocol, but the formats are different.

In Russia it’s mostly the keys model Dallas, which are working intercoms Vizit, Eltis, Z-5R, S2000-2, etc., Cyfral (keys DC2000А and Cyfral-KP1 etc.), Metakom.

Very rare and a resistor “pill” — they have read resistance.

2. “Droplets”. RFID tags, plastic round, oval or teardrop shape. Sometimes they are released in the form of bracelets or cards.

Inside — RFID-tag, as in the maps of metro, the “tweeters” on goods in supermarkets and other similar pieces. Basically “drops” can be short-range (Proximity, to be read at a distance of 10-15 cm) as a more “long-range” Vicinity markers that operate at a distance of 1 m, it is unsafe in this case.

In Russia often use Proximity-key-EM-marine, but there are also older HID label or newer MiFare, as in the cards metro.

3. Optical. Real dinosaurs. Somewhere in the provinces are still preserved. Such a key is a metal plate that is in a specific order nasverlennye holes.

Inside intercom is a photocell that detects whether the order nasverlennye holes.

The safety of the floor, the fake key is a trifling matter, and some intercoms with optical keys successfully and without a trace were opened with a nail file.

As the intercom system determines if the key fits?

The plant or the firm that installs intercoms in each key write special code. He was then stored in the memory of the intercom.

When you hold the key to the intercom, it reads the code and compares it with the values from my memory. If the key value is there, the door opens.

By the way, you can open multiple intercoms one key. We just need to register the code of the key to all the desired intercom. It is clear that intercoms should be compatible with the key.

Moreover, there are special modules that allow you to keep all the keys from one intercom and transfer them to another.

So will reset the intercom system you have in the entrance, and the keys do not have to change. Although, of course, the installer intercom may try to capitalize on this.

The exception, perhaps, only MiFare keys. They include writable memory into which is copied the unique ID of the intercom.

When the wizard “from the stall” clones a key, it copies only the factory code, but not the entry code. As a result, the intercom can reject such a key will protect you from clones. Copy the serial code can only service company.

How to make a copy of the key?

This will usually take the disc to a blank workpiece without any code. The wizard then reads the code from your key and records it on the disc.

As a result you get two of the same key. And since the code of the original key already saved in the intercom, then his clone would open the door.

Discs are rewritable and write-once. If you remember the word “finalization” when you burn a disc, take off the shelf pie, here it also applies.

Technically, you can pick up duplicator (programmer) keys based on Arduino or Raspberry Pi, and then make copies of the key for all occasions. Instructions the Internet is full of like and offers to buy a duplicator for a thousand or two rubles.

The main thing — not to miss with the type of intercom key.

So, some keys are designed for a frequency of 125 KHz, the other at 13.56 MHz and so on. In addition, they can be of different types. Remember the protection against clones that might be supported by your intercom.

Can the keys be demagnetized?

Sometimes, have a “tablet” or “droplet” in his pocket, and she after some time BAM! — and stopped working. And this nonsense every month. Something’s not right here. “Probably got demagnetized,” the most popular explanation.

In fact, these keys are not demagnetized. They even have a magnet there, and the usual magnets of the keys are not terrible.

The point is rather a simple lack of contact. Blanks are cheap, buy them in China wholesale for a few cents apiece, so that the contact may move, for example.

The buildings of the keys is usually not sealed. So if the key gets wet in your pocket or will frequently be in a humid environment for a long time it will last.

Theoretically, the keys can “kill” electromagnetic radiation or strong electric pulse.

For example, if you put the key in the microwave and turn on full power or thrust in the socket, work it stop. But powerful neodymium magnet like used in the shop for removing labels, the key is unlikely to harm.

Static electricity is also the keys are not good. If you wear a “pill” in my back pocket and often sit down, why synthetic fabric rubs against the key, it also will last long.

Finally, from the frequent use of “the pill” can be corny to push in the opposite direction and will cease to communicate with the intercom. Just push it back and it will pass.

What is the master key and where can I get it?

After the installation of the intercom specialist remains a special key. It can even be written something like: “the Master key. No one can give.”

But this key is usually the door cannot open. It is necessary to add the memory keys. The intercom code of the master key is stored in a particular area, so that the device could recognise it and respond accordingly.

Of course, mere mortals master key is not allowed. Otherwise, the service provider would be unable to borrow money for adding records about new keys the intercom.

But it is possible that a master key fits multiple intercoms. Or when some intercoms “tablet” is the master key, for others it is a regular key, which opens the door.

Here all depends not on the key, and which records are in memory intercom.

What happens if a master key gets lost?

Typically, the intercoms still have the opportunity to register a new master key. This, of course, the potential for hacking. But, objectively speaking, it is easier to get to the entrance, posing as a plumber than for something to crack.

Interesting to have a universal key, or “Rover”. Its code is registered in all the intercoms of the entrances of a house or yard.

“ATV” make for postmen, employees of municipal services, craftsmen, etc. Agree, this is much more convenient than to carry a garland of different keys.

Some RFID keys of the new format, for example, RF3.1, allow us to write codes up to 8 intercoms.

Often intercoms also support blocking keys. This is a security feature: once the door is opened the locking key, other keys do not work, and the door is locked. Remove the block can be either a master key or locking key (it all depends on the settings of the intercom).

By the way, sometimes blocking key set by mistake. So if the neighbors often can’t get in the door, check the locks whether your key access.

Is it possible to cheat the system?

Yes, now you can buy an emulator that mimics the keys of different types and outputs the desired value for each intercom. In emulators installed even display and keyboard that allows you to select a key and display its name.

Funny old thing, costs about 10 thousand rubles. But it is not without problems — not bypasses all protection, sometimes may not work.

And Yes, the intercom it will not crack, only pretending to be a copy of the key. Its programming will still be required and the keys themselves are aware of the intercom device-duplicator.

You can often hear that the intercom can incapacitate with a Taser. Yes, thin electronics a serious charge do not outsource. Mechanical shock 10-15 cm below the intercom panel the same effect. But it’s destruction of property and article of the criminal code.

Theoretically still possible to pull the door open. But to overcome the force with which the magnet holds the second part of the castle, you will need remarkable strength.

Some of the intercoms-“the pill” unable to open a battery “crone”. The method is humane and safe for the intercom, but it works rarely.

Is it possible to open the intercom smartphone?

Right now the market is gradually coming model NFC-enabled intercoms. Often they are installed in large offices, and very rarely in residential buildings.

If you have this option, your smartphone supports NFC, and intercom operates at a frequency of 13.56 MHz, might also abandon keys.

But for RFID, for example, in the smartphone must also be a Secure Element chip, and their presence even within the same model of smartphone is often different from market to market. If the chip is still there and other conditions are met, it might work.

There are also NFC-enabled adapters that make the old intercom system with new and promising. To open the door will be a “tablet” and smartphone.

Remember that you may be at the door in the cold and charging at home. And Yes, the iPhone will not. Apple has rigidly limited the possibilities for NFC in their devices.

What about access codes for intercoms?

Here, too, it all depends on the intercom. But most of the models that are installed in Russia now support the deployment of combinations of characters that allow you to open the door. It often works on the intercom “Visit” and less on the models of other manufacturers.

Combinations we deliberately do not publish — at least because the list for all the models is going to be long. But the master code from your intercom you almost certainly naguglit. Unless, of course, the installation code for door opening is not changed for your security.

It’s not the figures that are written on your key. For example, the length of the simple key for “tablets” DS1990A from Dallas is 6 bytes, 281474976710656 different combinations. You are unlikely to remember the combination of this length, but you can consider it on the keychain. The key is a 16 hexadecimal format, typically engraved by the laser on the surface.

PS there used to be a terribly banal life hack: keys with code 00 00 00 or FF FF FF could open all doors. These are the values recorded in the free cells of the intercom and participated in the comparison when checking the key. But this hole has been closed.

Read more •••


Please enter your comment!
Please enter your name here