Physical Cover PCI Compliant

Tamper Resistant Enclosure for POS / POI Terminals

A circuit board is the supporting element for almost every electronic hardware system. It’s used for the mechanical fastening and electrical connection of active and passive components. Almost all devices in the field of information technology consist of one or more printed circuit boards. For this reason, the physical protection of security-relevant components is essential. The challenge is to protect one or more chips on a circuit board against an attacker who can control the device in a hostile environment. It is assumed that the attacker is an expert in several areas necessary for the creation of the device and that he has unlimited time, unlimited tools and all available technology on hand.

Security certifications, according to PCI Security Standards Council or Common Criteria, require a physical security barrier for higher certifications to assure that it is difficult to penetrate or remove, in order to protect PIN-accepting devices such as payment or health terminals from manipulation. The physical barrier is not viewed independently, but as part of a multi-layered security approach, with the associated anti-tamper software to detect physical intruders. For this reason, the physical integrity of the barrier is checked actively and continuously by a battery-buffered circuit. In the past, simple flex foils or so-called MID plastic hoods (Molded Interconnect Devices) with associated conductor tracks were regularly used. These two technologies have some decisive disadvantages compared to the current most advanced innovative technology MS2C (Metal Sheet Secure Cover) from ddm hopt+schuler, a secure cover made of metal with an integrated safety structure.

ddm hopt+schuler MS2C Tamper Resistant Enclosure

The MS2C secure cover with integrated security structure aims to detect manipulation attempts and counteract the physical attacks. The secure cover separates the safety-relevant from the non-safety-relevant parts of a system, in order to protect the device from malicious analyses and physical attacks such as drilling, lasering or etching. The protective cover consists of two metal hoods with mechanical lifting switches and a multi-layer integrated secure mesh. The web width and spaces between the meandering structure are 200µ by default, but can also be scaled. Each layer of the secure mesh has two layers with four connection points, which are positioned on a flexible lead wire. Attempts to penetrate the secure mesh lead to the destruction of the conductor traces and to open circuits which are recognized by the device or to be precise by the anti-tamper software and lead to an immediate shut down of the system.

From our years of experience, we know that solution developers pay particular attention to security, user-friendliness and manufacturability when choosing a physical barrier. In general, envelopes made from simple flex foils are considered to be complex to manufacture, but as a solution with the highest geometric security. After the area to be protected has been packaged three-dimensionally, the foil is then in many cases poured into a container with synthetic resin. There are two problems with this process. For one thing, the use of flex foil does not correspond to any assembly process that is common in the electrical industry. On the other hand, the foil is often damaged during assembly. In addition, conventional flex foils withstand high temperatures due to their nature. For this reason, attacks with heat are possible. Printed circuit boards or MID hood housings are less complex to manufacture, but are also less secure. Compared to a housing made of printed circuit boards, further restrictions regarding the geometry and connection of the hood have to be taken into account with MID hoods. In addition, the production of MID hoods is limited to single-layer structures from an economic point of view. The MS2C secure cover combines the high security of a foil solution with the production security of a hood. Due to the combination of different technologies, complex geometric shapes can be implemented just as easily as the connection of the protective cover with the device by using the flexible connection lug. Additional connection options can be implemented if required.

Advantages of MS2C Technology

• Maximum security
• Multi-layer security structure
• Individual design
• Shorten assembly times
• Reduction of process steps