Veratag's patent pending product is a MEMS (Micro-Electro-Mechanical Systems) resonator structure placed on a silicon chip that can be read and uniquely identified. The product relies on the unique nature of MEMS resonators to provide a number of advantages in terms of security as compared to encryption and other techniques.

Nature of MEMS resonators

While working at Cornell's Craighead Research Group, researchers ran into a problem that has plagued the MEMS resonator community for years: as hard as they tried to create identical resonator chips, no two chips ever behaved the same. Minute random process variations during manufacture always conspired to produce slightly different structures, which had a large impact on resonator behavior. Each chip had a unique spectral "voiceprint" that was as unique as a snowflake, despite the researchers' best efforts to force uniformity. They ultimately realized that they could "make lemonade out of lemons" by embracing this uniqueness, and MEMflakes^TM were born. With appropriate geometries, trillions of devices can be produced, each with a different voiceprint. The uniqueness property of these devices comes with an additional interesting and important property: they are unclonable. That is, given a voiceprint, it is impossible to create another MEMS chip with a matching voiceprint, because random process variation will not allow the copy's voiceprint to be 'dialed in' to the detailed voiceprint of the original. So, not only is each chip unique, it cannot be copied.

The device that activates the MEMS structures is called a reader, and can either be directly connected to a chip (as in lock-and-key applications) or coupled either electrically via antennas or optically. The reader applies RF energy to the chip in a way that insures that each of the resonators or resonant modes is excited at its natural frequency, and measures those frequencies in real time. The complex measured frequency spectrum or "voiceprint" will uniquely identify a given chip.

MEMS resonator signals are quite unique in terms of the sharpness of their frequency spectra. Standard electronic circuitry cannot mimic MEMS behavior, which means that not only are MEMflake^TM chips unique and unclonable, but their signals cannot be synthesized to "spoof" a reader. Furthermore, since the resonators are mechanical devices, they can be interrogated by readers in ways that prove they are MEMS resonators and not electronic imitators.

The combination of uniqueness, non-clonability, and non-spoofable properties yields a powerful new nanoscale technology platform that is low cost and fast and can be used to provide authentication, from small- to large-scale applications.

MEMflake™ advantages

The practical effects of the complex behavior of MEMS resonators provide MEMflakes^TM with key advantages over other technologies:

1)      a complex signal from a tiny footprint;

2)      a unique and differentiating signal that occurs naturally;

3)      a signal that is hard to reproduce using anything other than MEMS resonators.

For RFID-like applications , MEMflakes^TM have a number of practical additional advantages including:

• short read times -  read times are sufficient for most transactions
• cost effective – MEMflakes^TM take up little chip real estate, keeping costs low
• simplified backend - no encryption keys or other secret information that needs to be stored and transmitted securely
• invulnerable to conventional attacks – MEMflakes^TM are impervious to power analysis or reverse engineering
• CMOS compatible – MEMflakes^TM can be incorporated with existing RFID chip functionality
• low power requirements - allow MEMflakes^TM to be on passive tags.
• sufficient read range – similar to many other tags

 

 Comparison to encryption

Comparing MEMflakes^TM technology and encryption is a little like comparing apples and oranges. Although both do provide security, they do so in very different ways and are useful in somewhat different applications.

Encryption relies on an algorithm and a number called a key. While the algorithm is often widely known, the key is kept secret and its disclosure represents a possible security breach.  By comparison, there is nothing secret about a MEMflake^TM .  Knowing the identifying signature does not help to reproduce the signal.  That allows for signatures to be shared readily with third parties, even published on the internet, and eliminates the need for trusted third parties or a secure communications infrastructure to protect key data. In the RFID world, if an encryption key is discovered, a duplicate or clone of the chip can be made using another chip. With a MEMflake^TM, manufacturing a clone is a practical impossibility.

The advantage of encryption is that it can be used to disguise data resident on an RFID tag so that it cannot be read by third parties 'listening in'. In applications that require secure data transfer, encryption is an appropriate methodology. In many applications, particularly network-centric applications where readers are tied to a central networked database, simply knowing that a given identifiable chip has passed a given point is sufficient to satisfy the information needs of the user. In these applications, MEMflakes can replace encryption and minimize the costs and complexity of secure tags and their associated infrastructure. In applications where authentication is paramount and data has to be transfered but does not have to be disguised, hybrid MEMflake^TM-RFID chips can be deployed without the costs and overhead of encryption. In applications where both guaranteed authentication and data enryption are required, the combination of MEMflakes^TM and encrypted RFID can be deployed.