Do you know if exists a write-once-read-many (aka: WORM) USB flash or SD memory?
I need an electronic write once memory to meet law requirements for storing sensitive data, and I want an alternative to my actual solution of CD-R discs.
I found that SanDisk produced some WORM SD card, but now this kind of card seems to be out of production.
Given that DVD/CD drives are now more often external and connected via USB, they do not conflict with your request for an alternative.
I agree that CD-R discs are not ideal, especially after having a couple go bad on me after a few years. But you could instead upgrade to the compatible M-DISC, where M stands for Millennium.
While I don't know if an M-Disc will really hold for a thousand years, or that anyone will care about your data at that time, M-Discs have become much cheaper in the last few years. For example on Amazon, Millenniata 4.7GB M-Disc Write Once and Read Forever, Read 16x/Write 4x Speed, 50 Pack goes today for $124.95. You can also today find Blu-ray M-Discs.
You would have to choose carefully your DVD/CD drive for compatibility with M-Discs. I have found this M-Disc's list of devices that can write, but I cannot vouch for its completeness.
If you wish to go up another notch, you could pass to WORM tape cartridges, but there you are multiplying the price-tag by a factor of 10.
SD WORM cards seem to have gone out of fashion, while Flash-using WORM seems not to exist. So as far as I can see, the options that are left are CD-R, M-Disc or tape.
For flash based memory I can't seem to find anything either. This talks about writing to the ones you're talking about but that doesn't get you any.
You could use a software to make a USB drive read-only like this one Softpedia download, but software is breakable and a fat32/64... system might not even recognize that there is security and go right through. The other recommendation would be to get one of the flash cards that has the lock switch, write your data, lock it, then break the toggle off... still, someone could probably switch it back with a paperclip or something.
Have you considered something like DLT, which has WORM media available?
DLT tapes have WORM media, but you might not have the option to add a DLT tape drive to the systems you're working on. You could probably find a DLT system that supports WORM for relatively little money these days, since LTO has mostly taken over for DLT.
It may also be worth noting that LTO has WORM media available as well, starting with LTO-3.
There is a company that may provides the WORM Card like solution. This company is called Embestor. They provide customized service.
