Google Scholar turns up a lot of applications in cryptography.  One reference that is very accessible to students (but not particularly deep) is "Singular Value Analysis of Cryptograms", Cleve Moler and Donald Morrison, MAA Monthly, Feb. 1983 vol 90., no. 2, pp. 78-87.  It's available on JSTOR.  http://www.jstor.com/stable/2975804