There are several known algorithms for Secret Sharing - see http://en.wikipedia.org/wiki/Secret_sharing
Simon On Tue, Mar 5, 2013 at 1:35 PM, Joe Hourcle <onei...@grace.nascom.nasa.gov>wrote: > On Mar 5, 2013, at 8:29 AM, Adam Constabaris wrote: > > > An option is to use a password management program (KeepassX is good > because > > it is cross platform) to store the passwords on the shared drive, > although > > of course you need to distribute the passphrase for it around. > > So years ago, when I worked for a university, they wanted us to put all of > the root passwords into an envelope, and give them to management to hold. > (we were a Solaris shop, so there actually were root passwords on the > boxes, but you had to connect from the console or su to be able to use 'em). > > We managed to drag our heels on it, and management forgot about it*, but I > had an idea ... > > What if there were a way to store the passwords similar to the secret > formula in Knight Rider? > > Yes, I know, it's an obscure geeky reference, and probably dates me. The > story went that the secret bullet-proof spray on coating wasn't held by any > one person; there were three people who each knew part of the formula, and > that any two of them had enough knowledge to make it. > > For needing 2 of 3 people, the process is simple -- divide it up into 3 > parts, and each person has a different missing bit. This doesn't work for > 4 people, though (either needing 2 people, or 3 people to complete it). > > You could probably do it for two or three classes of people (eg, you need > 1 sysadmin + 1 manager to unlock it), but I'm not sure if there's some > method to get an arbitrary "X of Y" people required to unlock. > > If anyone has ideas, send 'em to be off-list. (If other people want the > answer, I can aggregate / summarize the results, so I don't end up starting > yet another inappropriate out-of-control thread) > > ... > > Oh, and I was assuming that you'd be using PGP, using the public key to > encrypt the passwords, so that anyone could insert / update a password into > whatever drop box you had; it'd only be taking stuff out that would require > multiple people to combine efforts. > > -Joe > > > * or at least, they didn't bring it up again while I was still employed > there. >
