Your best bet would be to find some sort of channel for communicating with your future self that your adversary does not have access to. Other posters mentioned several such examples, with channels including:
keeping your long term memories (assuming that the memories couldn’t be tampered with by the adversary)
Swallowing a message, getting it as a tattoo, etc. (assuming that the adversary can’t force you to do that)
Using some sort of biometric lock (assuming that the adversary can’t get a proper sample with causing detectable alternations to your blood chemistry which would be detectable in the sample)
My personal addition: tell your friends/neighbors/the news the story. Unless your adversary can make you lie (or take your form or use mind magic or whatnot), these people can act as the channel you need.
If you don’t have a channel of that sort, I believe you are out of luck. A formal proof eludes me at this time; I’ll post again if I figure out out.
Your best bet would be to find some sort of channel for communicating with your future self that your adversary does not have access to. Other posters mentioned several such examples, with channels including:
keeping your long term memories (assuming that the memories couldn’t be tampered with by the adversary)
Swallowing a message, getting it as a tattoo, etc. (assuming that the adversary can’t force you to do that)
Using some sort of biometric lock (assuming that the adversary can’t get a proper sample with causing detectable alternations to your blood chemistry which would be detectable in the sample) My personal addition: tell your friends/neighbors/the news the story. Unless your adversary can make you lie (or take your form or use mind magic or whatnot), these people can act as the channel you need.
If you don’t have a channel of that sort, I believe you are out of luck. A formal proof eludes me at this time; I’ll post again if I figure out out.