You want a pen plotter. Or its cheaper, more expensive cousin, the Axidraw.
> As you mentioned fire-resistance, do you also use some sort of fire resistant paper? Because I don't think anything in made of paper would survive an actual fire.
Actually there are document safes with built-in insulation which will keep regular paper documents safe for time X under fire conditions Y (it's some EU standard classification). Certain ways of mounting safes makes them intrinsically fire-safe(r) as well.
Huh. It's cheaper (worse quality) but costs more money?
[1] https://www.amazon.com/pen-plotter/s?ie=UTF8&page=1&rh=i%3Aa...
Elliptic curves are nice because they allow short keys, for example curve25519 uses 32 byte keys that are pretty reasonable to copy manually (44 base64 chars or 64 hexs).
Meaning you could use PBKDF2 of your favorite passphrase as your private key, then keep it in organic memory.
Personally, I would love to see a strategy for generating a private from an analog picture.. But I don't see a good way to do it reliably.. Maybe one could generate it from error correction bits in a QR code.
I'm working on a blog post on deterministic passwords (i.e. not keys for ECC), but I guess that if you really want determinism you can do something similar, maybe sha3.512 and "cut" a 256-bit ECC key.
This is the post, still a draft. Hopefully I'll publish it next week, but if you have any comments, they are more than welcome! https://medium.com/@0x0ece/how-i-manage-my-passwords-technic...
Not clear exactly what you meant, but but deriving a key from a photograph shouldn't be that difficult. A good perceptual hash should work, maybe some preprocessing is needed (straighten/crop/normalize/resize). It helps that the amount of data in an image is absolutely massive compared to typical key size.
So you can do something similar. Pick a deterministically generated bit string, and use as key the next prime number (you need to do it twice, for p and q).
You certainly get less security and I unfortunately don't have any reference to quantify that.
As I was saying in another post, I'm writing about deterministic password generation (i.e. not RSA keys). Draft here: https://medium.com/@0x0ece/how-i-manage-my-passwords-technic...
Before: 2^2048, After: 256^20 = 2^160 (when using a 20 key password. Obviously you could use looong random generated passphrases, but then you could just base64encode your key?)
Symetric and asymmetric encryption don't have the same key length standards.
As you mentioned fire-resistance, do you also use some sort of fire resistant paper? Because I don't think anything in made of paper would survive an actual fire.