Is there a big shot who can provide some ideas:

I want to prove that I am who I am right now!

I hold a newspaper from today, or point to the latest Bitcoin block hash, to prove that the video or photo being taken is made today.

But there is a problem, if today is the 10th, and I film a video pointing to the Bitcoin blockchain hash from the 1st, saying today is the 1st, and I predict that the highest price of Bitcoin on the 9th is xxx.

How can we avoid this kind of cheating?