Tips on encryption for storage at rest (AES, SHA??)

I wanted to know what is the best way to encrypt storage at rest. Lets say financial information for 1000 users is on a system. Besides making sure nobody unauthorized gets to how do we encrypt the data that is being used everyday so that if开发者_开发问答 god forbid they get it, it should be impossible for them to decode or read?

I believe AES is a correct measure?? How can i implement AES using PHP for phpmyadmin data?

Neither SHA nor MD5 are encryption algorithms, so forget them for now.

The answer to your question is more organizational then technical. First you need to identify what storage you plan to use for the data. If it is the DBMS, then (a) it can offer certain encryption and authentication mechanisms, and (b) you can store the files of the DB on the encrypted storage.

If you have files (either the data itself or the DB with the data), you can store them on encrypted disk. This can be an encrypted NTFS disk or virtual encrypted disk (the one which resides in a file and is mounted as a virtual disk by software).

If you create backups of the data, then backup tools usually offer encryption mechanisms too.

In all of the above cases used algorithms don't matter too much: modern algorithms, offered by above mentioned mechanisms, are secure enough given that you choose 128-bit or larger key for symmetric encryption and choose long passphrase (more than 22 characters if you only use [A-z0-9] alphabet for 128-bit symmetric encryption).

There exists symmetric encryption and public-key encryption (PKI encryption). PKI lets you encrypt the files using public keys (private key is used for decryption), and one of the benefits is that you can encrypt the data for several different private keys. This means that any of the given set of keys can be used for decryption, and the owner of one key doesn't need another key for decryption. The benefit is that you can assign keys to certain users or roles instead of sharing a single passhprase.

The above is just a small guideline and you need to learn a lot (or better involve a security specialist) before you implement the solution, cause security made wrong is worse then no security at all (cause it gives false sense of protection and this makes people careless).

That depends on your platform; most modern operating systems offer disk encryption options with various degrees of security. Note that SHA and MD5 are hash algorithms and thus unsuitable for encryption.

I'd base my choice of algorithm on the capabilities of the system that is supposed to work with the data. Some CPUs have special instructions for AES processing, which gives a significant speed boost here; also, there are harddisk controllers that include encryption support.

Dedicated hardware has two major advantages: it is significantly faster, and it is more difficult to retrieve the symmetric key as a prelude to stealing the actual disk drives.