The patent pending product is a MEMS (micro-electro-mechanical systems) resonator 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

A MEMS resonator is essentially a bell, or string like on a violin, or tuning fork made at micron scale on a silicon chip.  These mechanical devices can be activated, aka ringing the bell, plucking the string or hitting the tuning fork, and vibrate at high frequencies.

MEMS resonator signals are fairly unique in terms of the sharpness, or quality, of their frequency peaks in high frequency ranges.  They are so unique that duplicating some of the characteristics of MEMS resonators can only be done using other MEMS resonators.  In addition, MEMS resonators can be interrogated in a manner which can prove that they are, in fact, mechanical resonators and not other types of electronics trying to imitate that behavior. 

While developing MEMS-based resonators, the researchers at Cornell University were having quality control issues because identically manufactured resonators produced slightly different sets of high frequency analog signals.  This problem became an opportunity when they realized that each resonator is as individual as a snowflake  Even if they wanted to make a resonator with a given frequency signal, they could not achieve the quality control necessary to do so. With trillions of trillions of signatures being possible, making a specific resonator would take almost as many tries costing millions of dollars. 

The combination of these two traits, a unique behavior that is only produced by MEMS resonators and the inherent production variability that prevents making a MEMS resonator at particular frequencies, combine to create a unique opportunity to make a non-clonable nanoscale device.

MEMflake™ advantages

The practical effects of MEMS resonators provide MEMflakes with key advantages:

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 besides a MEMS resonator while using a MEMS resonator is difficult given the natural production variation.

MEMflakes are ideally suited for RFID applications that require authentication because they are unique and can not be reproduced in the same form factor.  For applications in RFID, MEMflakes have a number of practical additional advantages including:

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

 Comparison to encryption

Comparing MEMflake technology and encryption is a little like comparing apples and oranges although both provide security. 

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.  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 to protect key data.

In the RFID world, if an encryption key is found, an essential duplicate or clone of the chip can be made from another chip.  With a MEMflake on the chip, manufacturing a clone is a practical impossibility.

The biggest advantage of encryption is that additional data on an RFID tag can be masked so that it can not be read easily by third parties.  MEMflakes can replace encryption where only a serial number is being encrypted to identify a tag, and can be used in conjunction with encryption as an added security layer when additional sensitive data is to be stored on the tag.  MEMflakes alone can not hide other data and are strictly an authentication methodology.