Re: Encryption Advice

On Fri, May 19, 2006 8:54 am, Lawrence Kennon wrote: > For an ecommerce site where sensitive data is stored > either in files, or in a database, have you used some > form of encryption to protect your customer's data? > > I have a client who currently uses a Perl scripted > shopping cart that stores orders (including credit > card numbers) in plain text files on a shared server. > The security of these files depends purely on the > user/file system security measures enforced by the > hosting company (which I think is a reasonably good > company, but still I don't see it as being > sufficiently secure). DO NOT STORE CREDIT CARD NUMBERS!!! Period!!! If your PHP script can access them, then they are too accessible to the Bad Guys. It's that simple. > I am going to rewrite the shopping cart using PHP and > was looking into ways to protect the data. Using GNU > Privacy Guard (gpg) seemed like the ideal method > because I could store the client's public key on the > server to encrypt orders and the customer could then > download the encrypted files and decrypt them on his > PC with his private key (the client manually submits > orders through his "store front" merchant account). I > know this is a somewhat archaic procedure but it works > sufficiently well for this client. Just get a friggin' online merchant account, and process the orders in realtime. It's just not that expensive, and will save your client HUGE MONSTROUS amounts of risk. You can set up a recurring charge if you think you "need" the CC# for that -- and then you get a Tx # from the merch and you do NOT need the CC#. > However the hosting company won't support gpg so that > leaves me with PHP mcrypt functions which I think > would work very well, except for on thing - how to > protect the secret key which now has to be on the > server? It does? Look, if you absolutely insist doing this the wrong way, AT LEAST make the client upload the key for decrypting and then ERASE the key immediately -- Or better, make him paste it into a big ol' textbox on an https server, and never have it hit the hard drive at all. > Any ideas/suggestions/experience along that line? Years ago, I was gonna do what you propose, because my client was too cheap to get a cert and pay the online merch fees. Thank GOD people on this list stopped me. Remember that game "hot potato" as a kid? CC#s are hot potatos. Get it, process it, nuke it. Fast! -- Like Music? http://l-i-e.com/artists.htm