Cisco open-sources experimental cipher Cisco is offering up an experimental cipher which, among other things, could help preserve the anonymity of data in cloud environments. In putting what it calls “FNR” (Flexible Naor and Reingold) into the hands of the public, The Borg says its work is currently experimental rather than production software. Cisco software …
This seems to be a very inefficient cipher. It needs seven rounds to be secure, but each round includes an AES encryption as the f-function. A stream cipher using AES would be a simpler way to secure data of arbitrary length - but just XORing stream cipher output to the data is lacking in security in some ways that this addresses. However, there are other ways to improve the combiner that have less overhead, so I can't be optimistic that this will get widespread adoption.
The Flexible Naor and Reingold figures proved to be a big hit with focus group participants. The flexibility in the Naor makes it easier and more fun for users to express their interpretation of the nightmarish horrors inflicted on Reingold by the Naor during their 2,000 year conflict.
Parents also cited the flexibility as a purchase decision driver. The razor tipped barbed spines of the Naor and the Twin Swords of Reingold in the static versions have been implicated in more than 1 million incidents of nocturnal carpet ambush when not stored properly at night. The flexibility of the new figures reduces the potential for foot puncture by more than 60%. Available at retailers for Hanukkah 2015.
It's a tweakable cipher (encryption depends on secret key plus something publicly known which varies with each record, like a record number or a person's name) designed for encoding very short bit strings without increasing the length of the data. Think of storing encrypted credit card numbers in a database without increasing the size of the field.
For efficiency concerns, the authors point out that AES is directly supported by modern hardware.
It therefore isn't directly comparable with AES in CTR mode or nor with GCM. Nor is it intended to obscure message lengths or provide message authentication.
Whether this is an acceptably efficient and more secure solution than other approaches I will leave to professional cryptographers to decide.
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