Drag File in Data URI format from Browser to Desktop

As this blog post points out, there is a way to download files via drag and drop from browser to desktop.

I want to drag a file in data uri format (e.g. "data:application/octet-stream;base64,eNcoDEdFiLEStuFf") to the desktop. I cannot provide a full URL to a server download due to security reasons (file needs to be handled clientside).

When I try what's given in the example of the blog post, a file which content and name is the current timestamp is created:

item.addEventListener("dragstart", function(evt) {
    evt.dataTransfer.setData("DownloadURL", "data:application/octet-stream;base64,eNcoDEdFiLEStuFf");
}

I already tried changing the format parameter, tweaking the format of the data a little and deconding beforehand but nothing works, I never get any of my data onto my desktop. Is there any way to accomplish what I am looking for, at least in some browsers?

By the way, we do not use jQuery. As a result, it might be interesting if there is a solution with jQuery but this will most probably not be applicable for our project.