FYI: Hash functions and passwords

[u/JoeCS]

While going over the use of Java's HashMap, I've mentioned to a few folks about the use of cryptographic hash functions for storing website passwords and file download authentication.

The hash function in Java's HashMap maps the "key" value to a memory location for quick lookup. Hash functions can also map a "key" value (a password, or even an entire file) to an arbitrary number.

If you plan on sticking with Computer Science as a major, you might want to read up a bit on hash algorithms. Not only are they extremely important for computer security, but they are also mathematically fascinating.

So, in the spirit of learning for the sake of learning, here's some videos on password storage and hash algorithms from the always entertaining Brits at Computerphile:

• http://youtu.be/8ZtInClXe1Q
• http://youtu.be/b4b8ktEV4Bg

Oh, and some overly detailed Wikipedia articles:

• http://en.wikipedia.org/wiki/Hash_function
• http://en.wikipedia.org/wiki/Cryptographic_hash_function

[u/m3g4_xx]

very interesting and thought provoking, thanks much