encryption - php halite file decryption "on the fly"

Question

hello i tried to do some encryption on files with paragonie/halite (or with php open_ssl; it doesn't matter)

the problem is that how can you open a file or img without first decrypt it and save it as a new decrypted file (the whole purpose of encryption is gone)

1. what i want is there is a encrypted file or img then
2. open the file / img and decrypt and show it or downloadable for user
3. these steps without to store the decrypted files first on disk (then its available without encryption)

You can do it with unlink the file after but i think that's not the correct way to do it i think. But what is the best way?

And how to do it with images which has to be available longer (show instead of download)

Answer 1

等待大神答复