I was looking at Time Capsule cryptography? and came up wth this idea.
Is there a way to store a secret such that the creator must update it or the secret will be decrypted and anyone can access it?
I use this algorithm to encrypt the message, $enc(M)$, now if I don't update, $update(enc(M))$, then $M$ will be publicly known with high probability after some given time $t$
One idea was to use the Time Capsule cryptography to encrypt a (URL, key) pair that points to my data, and the update function would be me moving the data to another URL. I feel that this is kind of cheating though, since I could just as easily write a script to give public access to the computer if I don't log in (for example) for a fixed period of time.
So, for this problem let's say that we don't have access to a server and $enc(M)$ must be publicly known and contain the message $M$. i.e. this should become a Time Capsule crypto algorithm if I never perform an update.
I have a feeling this may be impossible, if so could you give a high level proof of why?