Good Read.

I don't know much on the subject and found it very interesting, think you've inspired me to find out abit more.

Thanks,

Chris.

Yes, I forgot to add a title when I submitted it, so Cryptology was added to the title afterwards.  Cryptology includes both Cryptography (securing messages) and Cryptanalysis (defeating cryptography/"codebreaking").  I think the title was probably chosen because it covers both Cryptography and Cryptanalysis, although I do focus more on the Cryptography side.

Thanks!

Thanks for the reference!  I read Singh's book myself a few years ago and found it very entertaining and informative.  If I recall correctly, he also discusses the future of cryptology:  'quantum cryptology'.  Unfortunately I've lost my copy (I think I loaned it to someone and never got it back), so I didn't reference it for this article; but I'd definitely recommend it to anyone who wants to know more about the history of cryptology.  Here's a link to it at Amazon:  http://www.amazon.com/exec/obidos/tg/detail/-/0385495323/qid=1123680339/sr=8-2/ref=pd_bbs_sbs_2/103-0153168-7501472?v=glance&s=books&n=507846

He also has another book, "Fermat's Enigma", about how one of the world's hardest mathematical problems was solved.  It's very good as well.  Here's that link:  http://www.amazon.com/exec/obidos/tg/detail/-/0385493622/qid=1123680339/sr=8-3/ref=pd_bbs_sbs_3/103-0153168-7501472?v=glance&s=books&n=507846

Thanks again!

A typo was discovered by Douglas Chrystall in the article.  In the section on Asymmetric Encryption, I wrote:

"You encrypt a message with your public key, and it can be decrypted by the receiver using your publicly available public key and their private key."

I meant to write:

"You encrypt a message with the receiver's public key, and it can be decrypted by the receiver using their private key."

Thanks for the catch Douglas!

Nice intro to a very complex field.
I particularly enjoyed your timeline image. 

Another further reading book I would add for those who love details is

Making, Breaking CODES: An Introduction to Cryptology.  ISBN 0-13-030369-0
http://vig.prenhall.com/catalog/academic/product/0,1144,0130303690,00.html

Another good book like the The Code Book mention in an earlier post is:

Crypto: How the Code Rebels Beat the Government Saving Privacy in the Digital Age. 

I find it goes into more details about the break through of Asymmetric Encryption how its relevant to the key distribution problem.

If Douglas hadn't caught it, I would have mentioned your public/private error.  In your image, (Figure 4) you have "Marian Rejewski beings work...1932" That would be "...begins work..."

OK SSL (Secure Sockets Layer) doesn't involve SQL directly, but I'm a little surprised you didn't include that in your Asymmetric Key section, because it is a heavy user of this technology to encript client data that may eventually be stored in a SQL DB.