Applied Cryptography, Bruce Schneier (Wiley Publishing, 1995) and
Secrets and Lies, Bruce Schneier (Wiley Publishing, 2004) deal with the practice and issues of computerized cryptography
Codes and Ciphers, Robert Churchhouse (CUP, 2002) gives a good briefing with many examples
Codes, Ciphers and Secret Writing, Martin Gardner (Dover Publications, 2002) is good on simple codes
Cryptography: A Very Short Introduction, Fred Piper and Sean Murphy (OUP, 2002) is a good briefing on modern trends
Cryptography: The Science of Secret Writing, Laurence Dwight Smith (Dover Publications, 1971) covers simple codes
General histories
The Code Book, Simon Singh (Fourth Estate, 1999) covers the story of codes
The Codebreakers, David Khan (Scribner, 1996) is the classic work on the history of codes
Specific histories
The Man Who Broke Napoleon’s Codes, Mark Urban (Faber and Faber, 2001) is the story of William Scovell
Navajo Weapon: The Navajo Code Talkers, Sally McClain (Rio Nuevo, 2002)
Navajo Code Talkers, Andrew Santella (Compass Point Books, 2004)
The Victorian Internet, Tom Standage (Weidenfeld and Nicolson, 1998) tells the story of the telegraph system
The history of codes
http://fly.hiwaay.net/~paul/cryptology/history.html covers the early history of cryptography
www.axsmith.net/encryption.htm
www.bbc.co.uk/history/ancient/egyptians/decipherment_03.shtml
www.brooklynmuseum.org/exhibitions/2003/egyptreborn/ancientegypt/k4/language/language05
www.freemaninstitute.com/Gallery/rosetta.htmhem.passagen.se/tan01/simsub.html has examples of simple substitutions
www.jproc.ca/crypto/crypto_hist.html has a timeline of cryptography
www.murky.org/archives/cryptography/has lots on history and development
www.simonsingh.com/ website of the author of the excellent The Code Book
www.thebritishmuseum.ac.uk/compass/ixbin/goto?id=OBJ67home.ecn.ab.ca/~jsavard/crypto/entry.htm
www.vectorsite.net/idsearch.html tells the story of codes with plenty on their American history and on breaking codes
www.world.std.com/~cme/html/timeline.html has a chronology of cryptography
Sites for children and beginners
http://search.looksmart.com/p/browse/us1/us317837/us317922/us903634/usl0124254/ has links to sites for children
www.google.com/intl/xx-piglatin/ translates messages into Pig Latin
www.scouting.org.za/codes/
www.10ticks.co.uk/s_codebreaker.asp allows you to email coded messages to your friends
Sites with specialist information
ftp://ftp.pgpi.org/pub/pgp/6.5/docs/english/IntroToCr ypto.pdf is a comprehensive site on all aspects of modern cryptography
http://members.tripod.com/~mr_sedivy/colorado44.html shows the cowboy branding alphabet
http://starbase.trincoll.edu/~crypto/historical/railfence.html for rail fence and scytale ciphers
www.aldertons.com/index.htm is a cockney rhyming slang dictionary
www.cia.gov/cia/information/tour/krypt.html the CIA website on ‘Kryptos’
www.cockneyrhymingslang.co.uk/cockney/ is a cockney rhyming slang dictionary
www.codesandciphers.org.uk/documents/ includes the 1944 Bletchley Park cryptographic dictionary
www.comsoc.org/livepubs/cil/public/anniv/pdfs/hellman.pdf is an article giving an overview on modern public cryptography
www.cs.dartmouth.edu/~jford/crypto.html gives background on quantum cryptography
www.elonka.com/kryptos is a site about the ‘Kryptos’ sculpture
www.fas.org/irp/world/uk/gchq/index.html is an unofficial website about GCHQ
www.gchq.gov.uk/ website of the UK signals intelligence headquarters
www.geocities.com/Vienna/4056/cipher.html shows the Elgar code
www.history.navy.mil/faqs/faq61-2.htm contains information on Navajo code talkers
www.infosyssec.org/infosyssec/cryl.htm has lots of background and current information on security
www.nationalarchives.gov.uk/spies/ciphers/default.htm
www.profactor.at/~wstoec/rsa.html has a step-by-step guide to public encryption
Miscellaneous other sites
http://elonka.com/UnsolvedCodes.html
http://eprint.iacr.org/ an archive of papers on cryptology
http://mad.home.cern.ch/frode/crypto/ lists many papers on post-war codes
www.faqs.org/faqs/cryptography-faq/part01/index.html answers your questions on cryptography
www.gchq.gov.uk/codebreaking/ is the site of the British government’s communications experts, and has puzzles and games
www.nsa.gov/history/index.cfm is the website of the USA National Security Agency
www.nsa.gov/museum/index.cfm is the website of the national cryptologic museum in the US
www.puzz.com/cryptoquotes.html has cryptograms of sayings by famous people
www.spymuseum.org/index.asp is the website of the international spy museum in the US
www.und.nodak.edu/org/crypto/crypto/.sample-issue.html is the website of the American cryptogram association, which was set up in the 1920s
Computer short cuts and symbols
en.wikipedia.org/wiki/Leet has an alphabet of leet symbols
http://tronweb.super-nova.co.jp/characcodehist.html has a brief history of ASCII character codes
www.acronymfinder.com/ gives definitions for acronyms and abbreviations
www.lingo2word.com/lists/txtmsg_listA.html txt lingo
www.microsoft.com/athome/security/children/kidtalk.mspx? is a parents’ guide to computer slang
www.smsglossary.com/what-is-sms.html
www.techdictionary.com/emoticons.html is a dictionary of text short cuts with symbols
www.t-mobile.com/mytmobile/communication/messaging/shorthand.asp is about text short cuts