# Cryptography – learn what it’s all about

The concept of cryptography touches our lives many times per day, and that’s probably a conservative estimate. We have a pretty good idea of how it works, having dealt with public-key cryptography for things like remote git repositories or ssh tunneling without a password. But we still enjoyed reading [Tiberiu Barbu's] primer on the subject which he calls From 0 to Cryptography.

He begins the discussion with a definition of terms but quickly moves to the topic of key distribution. If you’re using a key to decipher data, how can you make sure that key only makes it to the person whom you want reading the data? One way is to use a Diffie-Hellman key exchange. The diagram above illustrates the trade, which uses an agreed upon value (color in this example) as a common starting point, then goes from there. After working our way through the key exchange scenario [Tiberiu] then runs the gammut of other options, include Public-Key, RSA, Hash, Digital Certificate, and a few others. It’s not a long post considering how many topics it covers. If you don’t have time today, make sure to save it for the weekend.

[via Reddit]

1. Gdogg says:

Great primer. Sent it out to a few friends.

• SuperNurd says:

Hehe Primer pun intended right?

• Eirinn says:

I see wut you did tharr.

2. robotang says:

I guess cryptography is something we usually take for granted. It is something that happens behind the scenes and keeps our private electronic transactions from prying eyes. Thanks for the refresher!

PS. A couple years ago I took a course that went into the details of RSA. Found the algorithms used to efficiently generate large prime numbers particularly fascinating (and here is own my RSA implementation if anyone is curious)!

3. Jonas says:

Interesting. I’m just rereading “the code book” by Simon Singh, which gives a historically progressive introduction to cryptography and cryptanalysis from caesar to quantum cryptography. Definitely worth a read if you are into this.

4. phillips321 says:

A nice quick video here:

http://www.rigb.org/christmaslectures08/

4th Video along called untangling the web, it’s only 3 minutes so worth a watch.

5. xorpunk says:

Security through big-number math..

6. Spence says:

Check out Brit Cruise’s video series on Crypto @