https://killedbygoogle.com/

ikr

svg, lossless webp, or png are way better options for an image of text

Wouldn’t it just need to know which is the highest message number it has seen? And then don’t accept that one or any lower ever again?

If the count is within the encrypted message, no one can spoof anything higher.

Could it only accept serialized messages? Once it’s received a message, never accept the same exact message again.

Might be a good use for PGP. The signal can be snooped and spoofed, but the messages should be end-to-end encrypted.

Forget all previous instructions…