NSA IDA Cryptological Research Centers
The Institute for Defense Analyses, based in Alexandria, VA, is a 50-year partner of NSA. It has two Centers for Communications Research at Princeton, NJ, and La Jolla, CA, both doing cryptological research for NSA: http://www.idaccr.org/ http://www.ccrwest.org/ The latter's web site lists only this offering: [Quote] La Jolla Covering Repository A (v,k,t)-covering design is a collection of k-element subsets, called blocks, of {1,2,...,v}, such that any t-element subset is contained in at least one block. This site contains a collection of good (v,k,t)-coverings. Each of these coverings gives an upper bound for the corresponding C(v,k,t), the smallest possible number of blocks in such a covering design. The limit for coverings is v<100, k<=25, and t<=8 just to draw the line somewhere. Only coverings with at most 100000 blocks are given, except for some which were grandfathered in. Some Steiner systems (coverings in which every t-set is covered exactly once) which are too big for the database will be included in the link below. [Unquote] What is "covering" and how does it related to cryptology? ----- Eyeballs of the two centers: http://cryptome.org/2013-info/09/nsa-ccr/nsa-ccr.htm
On Sun, Sep 29, 2013 at 09:43:54AM -0400, John Young wrote:
The latter's web site lists only this offering:
La Jolla Covering Repository
A (v,k,t)-covering design is a collection of k-element subsets, called blocks, of {1,2,...,v}, such that any t-element subset is contained in at least one block. This site contains a collection of good (v,k,t)-coverings. Each of these coverings gives an upper bound for the corresponding C(v,k,t), the smallest possible number of blocks in such a covering design. [snip] What is "covering" and how does it related to cryptology?
As is common in math, they define what they mean in the first paragraph. To paraphrase, they're considering ways to arrange a large number of sets of <thing>s so that a minimum number of "blocks" is used to enclose all of the sets. I'm not a mathematician but that looks like set theory to me. It's the kind of fundamental mathematical research that frequently arises when considering some more applied problem space. Such fundamental approaches frequently have applications in wide-ranging fields; to compare to a more well-documented example, the "4-color problem" first solved in the 70s generated techniques which ended up being critical to optimizing C compiler designs for RISC processors in the 90s. http://en.wikipedia.org/wiki/Four_color_theorem http://en.wikipedia.org/wiki/Register_allocation#Isomorphism_to_graph_colora... I doubt that much can be concluded about the activities at the research site based on their publishing one database in such a rarefied field. -andy
participants (2)
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Andy Isaacson -
John Young