And where is the file stored mister I know better than you?
You talk about decentralization like the files are stored in the blokchain...
So you're going to store the files on your computer, allow people to connect to you...and let them download the file? Is this your business model?
Rather than doing that I would simply make an order form, the buyer completes the payment to a random address and at that point, he gets the files in the mail, there are already a bunch of scripts for that.
No need for encryption, decryption, no nothing.
But we have to overcomplicate everything just to make it look cool
The file stored in your PC computer, and then you can share it over the web or torrent etc.
Who said you will allow peoples connect to you ? You didn't understood the process and you shoot everything with non sense.
The process is really basic, you have to encrypt the file like you do with WINRAR and similar softwares, and then once encrypted, you upload it somewhere using torrent p2p way, or even online upload services to share it over internet and broadcast it for potential buyers.
Once someone buy it, you will receive instantly your money in your wallet (The one you choosen to encrypt your file or folder).
And the best thing here, you can use it in CMD mode to encrypt files using command line, not only using GUI.
And the main interesting thing here, is that the file can't be deleted by anyone once shared ... not like online services where files deleted in a certain time or as soon as something goes wrong ... file available 24/24 7/7 when you need to purchase it in your own PC computer.
Hope i helped you with my little explaination.