TECHNICAL QUESTION: I just found 20 BTC on my old harddrive

[BangkokLawyer]

No, I did not. Just a hypothetical question. Let's image I found 20 (or 2.000) BTC on an old hard drive, as a result of a mining operation in the BTC stoneage. Is there any technical evidence for this? Can I prove that this had been an old mining transaction and not money laundry or else? Does the Blockchain give evidence that I did nor acquired the BTC yesterday?