[johsoe]

Then you have to wait for the download every time you open the app.

This is an okay compromise tbh.

(They could offer a super secure option or whatever, I guess)

[readerrrr]

Actually you could just download the encrypted images without the unique key( for every image ) and then get the key on demand. Load the image into ram, decrypt, show the image and then erase everything.

[JoachimSchipper]

That would be more secure, but you still need to wait for the key to be downloaded on-demand - you don't exactly get butter-smooth scrolling that way.

(I like security.)

[readerrrr]

And you would have to be connected to the internet. That is a problem. The delay could be hidden behind a ui.

[emidln]

Snapchat doesn't work particularly well offline...