Today on 8.3.6 Multiple-Column Indexes I learned about the hash index technique:
SELECT * FROM tbl_name
AND col1=val1 AND col2=val2;
As they say: “As an alternative to a composite index, you can introduce a column that is “hashed” based on information from other columns. If this column is short, reasonably unique, and indexed, it might be faster than a “wide” index on many columns. In MySQL, it is very easy to use this extra column.”
Found an interesting article: About Secure Password Hashing.
Today I read Salted Password Hashing – Doing it Right which was a good run-down on how to do password hashing. The article linked to phpass: Portable PHP password hashing framework which is a library for hashing passwords.
I was looking for a good overview article that explained the process of password hashing and I found Password Encryption, Hashing, Salting Explained which was a pretty good run down.
On a related note I reread the Wikipedia page on HMAC.