Talk:Cryptography/Archive 1

BigCleanup deleted items

[[Image:Lorenz-SZ42-2.jpg|thumbnail|320px|The [[Germany|German]] [[Lorenz cipher]] machine, used in [[World War II]] for encryption of very high-level general staff messages]]
[[Image:Skytala&EmptyStrip-Shaded.png|thumbnail|The Ancient Greek [[scytale]], probably much like this modern reconstruction, may have been one of the earliest devices used to implement a cipher.]]
[[Image:Nsa-enigma.jpg|240px|thumbnail|left|The [[Enigma machine]], used in several variants by the German military between the late 1920s and the end of [[World War II]], implemented a complex electro-mechanical [[cipher]] to protect sensitive communications.  [[Cryptanalysis of the Enigma|Breaking the Enigma]] cipher at Polish [[Biuro Szyfrów]], and the subsequent large-scale decryption of Enigma traffic at [[Bletchley Park]], was an important factor contributing to the Allied victory<ref name="kahnbook" />.]]
[[Image:Smartcard.JPG|thumb|250px|A credit card with [[smart card]] capabilities. Smart cards attempt to combine portability with the power to compute modern cryptographic algorithms.]]
[[Image:International Data Encryption Algorithm InfoBox Diagram.png|thumbnail|One round (out of 8.5) of the [[patent|patented]] [[International Data Encryption Algorithm|IDEA]] cipher, used in some versions of [[Pretty Good Privacy|PGP]] for high-speed encryption of, for instance, [[electronic mail|e-mail]]]]
[[Image:Diffie_and_Hellman.jpg|thumb|left|[[Whitfield Diffie]] and [[Martin Hellman]], inventors of public-key cryptography]]
[[Image:Firefox-SSL-padlock.png|thumb|161px|right|Padlock icon from the [[Firefox]] web browser, meant to indicate a page has been sent in SSL or TLS-encrypted protected form. But note that a properly subverted browser might mislead a user by displaying some similar icon when a transmission is not being protected by SSL or TLS. Security is not a straightforward issue.]] 
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Do not delete please Robert Tito | Talk 14:43, 19 February 2007 (CST)

Shannon

In his 1946 and 1948 publications made clear what cryptography should be (refs follow) Robert Tito | Talk 00:50, 21 February 2007 (CST)

Article title, structure, relationship to other articles

While I've made edits to this article, I didn't originate it, and I have been wondering if a full rewrite is in order, with the understanding that many topics need to be introduced briefly here, with elaboration in their own articles. Even the title might well be tweaked — cryptology is not a subset of cryptography; cryptography is a subset of cryptology. Personally, I prefer to introduce cryptanalysis only after first introducing the basics of signals intelligence and communications intelligence, since there are many ways to attack a secure communications system.

I agree that the numbers about brute force attacks on DES were not helpful. Pure numbers are rarely that useful for assessing cryptographic strength, since brute force is the last thing to try. DES, if for no other than historical reasons surrounding its development and controversies, does deserve its own article.

As to symmetric vs. asymmetric cryptography, I quite deliberately avoided "public" and "private", which are totally appropriate in a sub-article on public key cryptography. At the level of an introduction, however, I have found it much more useful to start with "secret" vs. "other" keys, because "secret" is much more convenient when starting with a compare-and-contrast about symmetric versus asymmetric. A person new to the subject needs to know that both types must have a secret "something", with a flag that asymmetric cryptography has other features.

One of the reasons for having a sub-article on public key is to address key management, public key certification, and certificate revocation.

I'm concerned that some of the subsections here are jumping too quickly into mechanics without setting enough background.

Let's discuss a structure of crypto articles, and try to come up with an introduction and a logical set of more detailed subarticles. From my perspective, I can build and run a secure network, with multiple layers of security -- but I don't need to know how partial elliptical algorithms work.