I was recently recommended a set of smart cards that don't feature key backup methods. However they do have a way to import plaintext keys, meaning a key ceremony is the way to go for key redundancy. This yields very special requirements for a laptop being used for this ceremony for which I'd like to ask for a recommendation.Requirements:Must feature a removable batteryMust feature a (somewhat easily) removable BIOS batteryMust feature a removable driveMust be able operate without a persistent storage driveMust be able to boot from a CD / DVD either via USB or internallyMust feature at least three USB type A portsMust be able to operate with Linux derivativesShould have as much open-source firmware or security certifications as possiblePrice should be sub 500 USD if possible
Laptop for key ceremony?
laptop;security
I think the most useful way to answer this question is to start with the hardest part of the answer and work my way down  should have as much open-source firmware or security certifications as possible.  As such my starting point would be the coreboot page, since that lists systems which support opensource firmwareI'm picking thinkpads here. I'm familiar with them, and the removable parts are mostly trivial.On this list, the T60 look handy. many of these features are found on newer thinkpads, but its worth considering some of the modern, boneheaded moves lenovo has made. The newer ones have worse keyboards, and of course, you need to find a superfish free version. Go with intel graphics in any case. Further research shows that Ministry of Freedom sells somewhat newer models than my initial recommendation of a T60 preflashed and those are worth a look. That said, the features I like about the T60 are true here too. Lets go down your list. I have an R60, and its the 'cheap' equivilent of an T60 so I have a decent idea what the features are. Being a thinkpad, thinkwiki has a great rundown on the features.Yes, its an older machine, but I have them running reliably with minor upgrades. They're really nice machines with a low end SSD.Must feature a removable battery  Two latches and it pops outMust feature a (somewhat easily) removable BIOS batteryRequires removal of the keyboard and that's about it. 3-4 screws, and you don't even need a service manual to find it. Bit finicky, and I'd recommend a spudger and a small screwdrive (cross head). There's a video here on the process. Must feature a removable driveIts an old school thinkpad. One screw, pop out the cover, yank the driveMust be able operate without a persistent storage driveR60's USB bootable. I've done it a few times. Maxing out the ram might be an idea.Must be able to boot from a CD / DVD either via USB or internally  Yup. Onboard, standard ATAPI drive, boots off USB fine. Must feature at least three USB type A portsYesMust be able to operate with Linux derivativesAs an older machine, compatibility is solid. I'd be reasonably confident even running a full DE on it, though my machines run windows 10 or xubuntu/lubuntu. Should have as much open-source firmware or security certifications as possiblePrice should be sub 500 USD if possibleEbay prices are significantly below that. Could even buy spares. I strongly recommend maxing out the ram if possible. These are solid machines, and despite their age hold up well.