D-UP is Dierre’s patented anti-tampering system. The high security cylinder protects the lock from bumping attempts, one of the most common methods of opening a cylinder lock through the use of a so-called “impact” key.



The mechanism of the cylinder D-Up is based on the "desmodromic” concept which comes from the Greek "forced path".

In the absence of key the combination gorges combination are located in a position chaotic, each motion or vibration of the cylinder can cause the displacement of the gorges in an unpredictable manner. The encoding of the key corresponds to the shape of the track formed on the key. When the key is inserted into the cylinder, the gorges take the only possible position that corresponds to the encoding of the key.
The cylinder D-up is not amenable to the so-called "bumping” technique (widespread system for the illegal opening of cylinders), thanks to the system of desmodromic encryption (Declaration- ERSI ELF MEMBER dated 24/10/2008 for D-Up cylinders).

Reversible key

"Reversible" key refers to a key whose 2 sides of the key are equally operational, the user therefore should not attempt a given orientation to insert the key in the cylinder.


The D-Up system is composed of 10 gorges, each of which can have 5 different positions, and by 2 combination pins which in turn can assume two different positions. The effective combinations according to EN 1303 are 235920.

Blank key protection and duplication control

The D-Up cylinder is rated level 3 with respect to the degree of security against duplication of keys according to regulation ICIM 70R009. In fact D-Up key duplication can occur only by presenting the ownership card and is perfomed exclusively by Dierre S.p.A through Dierre Key Point centres. The marking is not printed on the key but only on the ownership card completely excluding the duplication from the key sample.

Safety against non-destructive burglary

The cylinder is fitted with a mechanism for the recognition and block of a forged key. In the case in which the key inserted in the cylinder allows positioning of the gorges in more than one combination (false key), the key is recognized and locked. The same also applies to the handling of the cylinder with picks; in fact, after having put the pins and gorges in the opening position in the absence of the correct key, the cylinder is locked even at a minimal rotation attempt.

Anti-drilling protection and key profile control

Anti-drilling protection is ensured by 2 elements, i.e. a ball and a plug made of hardened steel. The plate in the shape of a crescent moon protects the gorges and also performs the function of controlling the key's profile.

Resistance to burglary

The cylinder is provided with a module connecting bar, made of high resistance steel alloy that ensures a breaking load substantially greater with respect to the cylinder in brass.

Modular System

The principle of modularity used in the design of the D-Up cylinder consists in the production of independent modules which can be assembled at the request of the customer. The main form contains the safety mechanism and has a length of 30 mm. This module can be assembled independently of other modules and can later be mounted in the cylinders: key-key, key-knob or half-cylinder. In fact in all of these types the module with a safety mechanism is the same.