The new green card comes with a bunch of enhanced features. Although most of them are designed for security purposes, the implementation of RFID – Radio Frequency IDentification – is rather for improving efficiency. In fact, if anything, RFID might have undercut an otherwise more secure green card.
With RFID embedded in the new green card, a CBP officer is now able to read your card while you are still standing in line at the airport. This, hopefully, can get you through a port of entry a bit faster. But the problem is, anyone with a sophisticated reader can read the same information as well, all from a distance without you even knowing it.
Before you push the panic button, however, let me just say that USCIS isn’t playing around with all the hassle of redesigning the green card. They must have worked with LaserCard (the manufacturer) to make sure that any embedded data isn’t easily accessible by an unauthorized source. And people who can break an RFID encryption are probably working on other stuff than reading your green card anyway.
But it remains a privacy concern. Since you are supposed to carry your green card with you at all times, the thought that someone walking by may have just read your green card is simply uncomfortable. So you want to follow all instructions from USCIS with regard to the storage and carrying of your new card. In fact, according to Piers Fawkes at PSFK, his new green card arrived with a warning on the card sleeve:
We recommend use of this envelope to protect your new card and prevent wireless communication with it.
The little card holder is probably some sort of electromagnetically opaque sleeve that shields your green card from external readers. At a minimum, it will make contactless access to your RFID more difficult.
Wikipedia has a good article on RFID, with a large section dedicated to security and privacy risks of the technology. The Federal Trade Commission (FTC) published a consumer report several years ago that had a section called The ABCs of RFID – another good read if you want to learn more:
In RFID systems, an item is tagged with a tiny silicon chip and an antenna; the chip plus antenna (together called a “tag”) can then be scanned by mobile or stationary readers, using radio waves (the “RF”). The chip can be encoded with a unique identifier, allowing tagged items to be individually identified by a reader (the “ID”).