lattice reduction

[minhduc]

Hello
This is an extract from Rain Fall by Barry Eisler.

"Ever hear of a lattice reduction? It's a kind of code. The cryptographer encodes a message in a pattern, a pattern like the flowers in a symmetrical wallpaper design."

Would you like to explain the meaning of the name "lattice reduction" to me? Thanks.

 

[pwmeek]

I have a vague idea of what it is referring to, but don't know enough to come close to explaining it in everyday English, but I am willing to try:

It has to to with solving problems by mapping the problem to a lattice (a regular array of points in an n-dimensional space), simplifying the resulting vectors, and then "un-mapping" the simplified vectors to get the solution.

I doubt this has really answered your question, and I don't feel as though I understand it much better, myself.

When I read that book, I confess I just slid over lattice reduction without worrying too much about it. I think it is best to take Barry Eisler's explanation: "The cryptographer encodes a message in a pattern, a pattern like the flowers in a symmetrical wallpaper design," and accept that lattice reduction is intended (in this fictional context) to mean: "This is much too complicated for ordinary mortals to understand, but it is a very good encryption technique."

By the way, "the flowers in a repeated symmetrical wallpaper design" is a fairly vivid description of a two-dimensional lattice (mathematically speaking).

 

[minhduc]

Thank you very much for your help