This Java Script method have many disadvantages :. Now because of this end to end encryption, downloading files from Mega is bit different, like other file hosting sites you cannot download files from Mega with your Browser or any download Manager, Mega uses Java script to download files in within its site and then after completing it sends it to the browser.
nz is one of the most secure File Sharing and Cloud Storage which is actively focused on secure end to end encryption, this means files are encrypted both on upload and download.
