On Mon, 5 May 2008, Ariel Waissbein wrote:
[Moderator's note: Again, top posting is discouraged, and not editing quoted material is also discouraged. --Perry]Hi list, Interesting. Great work! I had been looking *generic* predicate encryption for some time. Encryption over specific predicates is much older. Malware (e.g., virus) and software protection schemes have been using some sort of "predicate encryption" or "trigger" for over two decades in order to obfuscate code. For example, an old virus used to scan hard drives looking for a BBS configuration files in a similar manner and some software protection schemes have encrypted pieces of code that are decrypted only if some integrity checks (predicates) over other pieces of the program are passed. Triggers/predicates are very promising. Yet, they are only useful in certain applications, since eavesdropping one decryption is enough to recover the keys and plaintext. I co-authored a paper were we used this same concept in a software protection application ([1]) and later we formalized this concept, that we called secure triggers, in a paper eventually publised at TISSEC ([2]). We were only able to construct triggers for very specific predicate families, e.g., - p(x)=1 iff x=I for some I in {0,1}^k - q(x,y,z,...)=1 iff x=I_1, y=I_2, z=I_3,...; and finally - r(x)=1 iff x_{j_1}=b_1,...,x_{j_k}=b_k for some b_1,...,b_k in {0,1} and indexes i_1,...,i_k (|x|>=k). While these predicates do not cover arbitrary large possibilities, they are implemented by efficient algorithms and require assuming only the existence of IND-CPA secure symmetric ciphers. In [2] we came up with more applications other than sofprot;) [1] Diego Bendersky, Ariel Futoransky, Luciano Notarfrancesco, Carlos Sarraute and Ariel Waissbein. "Advanced Software Protection Now". Core Security Technologies Tech report. http://www.coresecurity.com/index.php5?module=ContentMod&action=item&id=491 [2] Ariel Futoransky, Emiliano Kargieman, Carlos Sarraute, Ariel Waissbein. Foundations and applications for secure triggers. ACM TISSEC, Vol 9(1) (February 2006). Cheers, Ariel
Predicate encryption sounds very different from the work you are referencing above. (In particular, as we discuss in the paper, predicate encryption for equality tests is essentially identity-based encryption.) I refer you to the Introduction and Definition 2.1 of our paper, which should give a pretty good high-level overview.
--------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
