Combinatorics, Cryptography and Number Theory:

Mathematics Subject Classification	MacTutor History of Mathematics	Unsolved Mathematical Problems
Unsolved Mathematical Problems	Most Wanted List of Mathematics Problems	The Young Mathematicians Network WWW Site
Mathematics Departments on the WWW	USA Mathematics Departments	The Mathematical Atlas (by Dave Rusin)
The Online Encyclopedia of Integer Sequences (by Neil Sloane)	Favorite Mathematical Constants (by Steven Finch)	Free Refereed Electronic Journals
Another list of free electr. journals	Mathematics Archives (Univ. of Tennessee, Knoxville)	WWW Virtual Library (Mathematics)

Combinatorial People	Combinatorics Groups	Combinatorics Stuff
Combinatorics Net and Annals of Combinatorics	Algebraic Number Theory Archives (previously managed by N. Boston & D. Grayson, now at UC Davis managed by M. Zieve with help from G. Kuperberg)	Number theory ftp sites/calculator programs/archives
Crypto Conference papers Online	UCL Crypto Group	Quadralay's Cryptography Archive
Cryptographers' List	Another List of Cryptographers	ECCC-papers+books
Cryptography Research - Conference Papers Online	Ronald Rivest: Cryptography and Security (comprehensive list)	Cryptography Courses   (courtesy of Avi Rubin)
Theory of Cryptography Library	Crypto related publications online	Security & Cryptography Research Links