Need suggestions on how to create a website with an encrypted database

I want to create a website where a use开发者_Go百科r enters content (say a couple of sentences) which eventually gets stored in a backend database (maybe MySQL). But before the content leaves the client side, I want it to get encrypted using something on client like maybe javascript.

The data will travel over the web encrypted, but more importantly, will also be permanently stored in the backend database encrypted.

Is JavaScript appropriate to use for this? Would 256 bit encryption take too long?

Also, how do you query an encrypted database later on if you want to pull down the content that a user may have submitted over the past 2 months?

I'm looking for tips, suggestions and any pointers you guys may have in how to go about learning about and accomplishing this.

Thanks!

You shouldn't implement the encryption for the communication between the client and the server yourself, use SSL (https) for that. As for encrypting data in the database, you can always use MySQL's built-in methods, such as AES_ENCRYPT and AES_DECRYPT, see reference manual for details.

Look at http://www.farfarfar.com/scripts/encrypt/ (encrypt/decrypt).

Tried text/text/XXTEA with success.

However, that's about as far you can go with JS encryption.

As long as you're not using SSL/https, the main disadvantage is:

• A fuzz to protect the private key, (it can be done though, like a form field, not submitted, but requires user to enter value on each session.)

About searching/extracting data on encypted data, I belive nothing is going to work.

Well, to point out something: if it's client side encrypted, it'll likely also be easily decrypted, seeing as with languages like javascript, they're being handed the source code of your encryption scheme. Plenty of encryption schemes out there, AES, Blowfish, etc, but if the data is traveling on an encrypted connection, I suppose the encryption of the data only adds very little security, maybe packet sniffers locally installed or something to that effect.

I would also suggestion you look into using compression as well, I myself have used LZMA, Huffman, and even base64 encoding with javascript to at least obscure the content from casual observers. Point being, no matter how good the encryption, you're handing over the process to the client, and they can just view your source and be able to easily reverse the encryption, given that they know the encryption scheme and aren't to lazy to do a bit of Googling or searching on Wikipedia. I personally prefer compression because it also reduces the size of the data being sent, and unless one is trained in analysis of encryption and compression, it is isn't easy to figure out the compression being used from sniffing packets.

EDIT: But if you want high levels of security, I would suggest against using just compression, and instead, using an asymmetric encryption method like RSA or Diffie-Hellman encryption on data traveling between the server and client, as the private key will never be shared.

For client side, javascript or better, a Java application, would work (at least you can't right click -> view source with a Java app in two seconds). 256 bit encryption wouldn't take too long if you're just wanting to save a few sentences like you said. A modern processor with blast through that in milliseconds. Then, when it arrives at the server, encrypt it using AES or another powerful algorithm (note that the US government uses AES 256 for their Top Secret documents) before sending it to the database. (Also want to add that you can also store a hash (MD5 is a function readily available in PHP, you can opt for something like Whirlpool as well, but you'll have to find a library for that) of the data on a separate database, and check against it when you access it to ensure that your database hasn't been compromised)

For querying, I suggest PHP. Read the data, decrypt it, then send to the client (in still encrypted form), or if you want, and have the client decrypt it also, if you don't trust the networks the data is being sent through.

Here's a good source on Javascript and AES: http://point-at-infinity.org/jsaes/ My two saved links using RSA in javascript: http://www.ohdave.com/rsa/ and http://www.hanewin.net/encrypt/rsa/rsa.htm

As for the data being sent over the network encrypted, this is the kind of thing that HTTPS was made for. Nothing is transmitted in the clear. It's encrypted securely enough for most banks to trust it. Don't reinvent the wheel here; it'll never be as round as what a bunch of people who make wheels for a living have come up with.

Have your form submit to an https:// url (rather than http://), and the script/app at that URL talk to the database, encrypting and decrypting the data as needed. Javascript won't easily talk directly to MySQL anyway, and if you do all the encryption client-side, anyone who can get the page can still decrypt it (since by necessity the client would need to be given the decryption key as well).

Check out this blogpost: http://www.ravellosystems.com/blog/all-you-need-to-know-to-configure-ssl-offloading/

It takes you through all the steps you need to do to configure your webs server to serve content under an encrypted channel (a.k.a SSL termination).