Everybody can claim to be the most secure cloud storage service. We at Filen like to be transparent. So how does everything really work under the hood? Well, it's quite simple. When you upload a file to Filen's cloud storage, you actually don't upload a file, you upload chunks of encrypted text. Before you initiate an upload, your browser chunks your file into 1 MB pieces, encrypts them using AES-CBC 256 bit encryption and then sends the encrypted string to our servers. That way the actual file never leaves your computer. Even file names and metadata are encrypted.
When downloading a file your browser requests all chunks of the file from Filen's servers, decrypts them using the decryption key and then rebuilds the whole file again.
This way you can be sure that your file is always secure and not readable by anyone unless they have the decryption key. Not even we know what you have uploaded.