Difference between all the encryptions...

[dclamp]

1) What is the difference between MD5, SHA1...?

2) What encryption is best?

3) Can you encrypt an encryption? Like:


<PHP
$password = MD5(SHA1("mypass"));
?>

[penagate]

I recommend this Wikipedia article

Cryptographic Hash Functions (http://en.wikipedia.org/wiki/Cryptographic_hash_functions)

[RudiVisser]

For passwords, never use a straight MD5.

Always try to move away from using one form of encryption, I mainly use:
md5(base64(md5(base64("STRING"))));

But that's just me ;)

As long as you use the same encryption to encrypt as to match, it doesn't matter.

[superbovine]

1) What is the difference between MD5, SHA1...?

2) What encryption is best?

3) Can you encrypt an encryption? Like:


<PHP
$password = MD5(SHA1("mypass"));
?>


1. see the article pengate posted.

2. depends on your specifications and requirements.

3. "Can you encrypt an encryption?" What you mean to ask is "Can I encrypt encrypted data?" The answer is yes. It would be easier to use one encryption key double the size. You will have to do some research, but I am assuming using the same encryption scheme with two different keys might actually weaken the strength of the encryption. See http://weblogs.asp.net/despos/archive/2004/11/09/254647.aspx