I would like to make a steganographic file that can be decoded on multi-platforms, now & 20 years from now.

I don't want to do so with software that may be out of date when the message decode is attempted.

How would I do this?

  • 1
    $\begingroup$ Have you looked into the open standards regarding your encryption and steganography? $\endgroup$
    – zetaprime
    Jun 29, 2019 at 8:39
  • $\begingroup$ Have you considered that the current algorithms (AES, ChaCha etc) will in all likelihood have been broken within 20 years? Unless of course you use the venerable one time pad. It might be wise to reduce the time span, and transcript after say 5 years. Also read about the looming new dark age. $\endgroup$
    – Paul Uszak
    Jun 29, 2019 at 15:13
  • 2
    $\begingroup$ @PaulUszak Why do you believe that AES will be broken within 20 years? It has survived its first 20 years virtually unscathed. Why do you think the next 20 will be any different? $\endgroup$
    – forest
    Sep 8, 2019 at 1:17
  • $\begingroup$ @Emily: What exactly you mean by "decoder agnostic"? $\endgroup$
    – mentallurg
    Sep 8, 2019 at 11:16

1 Answer 1


I will assume you're referring to steganography in images.

The most important thing would be to use a color space that is likely to be recognizable 20 years in the future. For this, sRGB is a good candidate. It was created more than 20 years ago, in 1996, and it is still the most popular color space in use. It's safe to bet that, in 20 years, it will not be forgotten. You can use traditional LSB steganography to encode information. As long as the color space is preserved, it should be compatible with whatever future software you are using (or compatible software that is easy to find).

  • $\begingroup$ Would the downvoter care to explain what's wrong with this answer so I can improve it? $\endgroup$
    – forest
    Sep 8, 2019 at 2:44

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