What is the best support to store data long-term?

Question

I have been facing this question many times when making backups for home.

I would like to understand what is the best way to store data for the long-term (i.e.: 50 years). The requirements of the support are the following:

1. Should be small enough to fit into a closet;
2. Should be relatively cheap (no exotic tachnology);
3. Should be possible to encrypt (e.g.: veracrypt/truecrypt file container);
4. Should not perish (e.g.: optical drives sometimes tend to detatch the metallic part impressed by the laser from the plastic support);
5. Should be physical (i.e.: no cloud);
6. Does not need to be rewritable (I like to make "snapshots").

Assuming that in 50 years somehow there will still be the technology to access any support available today to memorize data, what is the best way to store it, given the requirements listed above?

Answer 1

I am not sure if you will get all the listed requirements, usually if you want something cheap you will sacrifice elsewhere. That being said, you should look at 'MDisc' as a backup medium, also 'magnetic tapes' would also be worth looking into as an alternative.

TechTarget.com - did a write-up on some of the options for cold storage backups - Demand for cold data storage heats up

This image from the article provided a good comparison between some of the different options.