We will soon add more pages explaining how we are doing the encryption. Few details are already mentioned in the homepage as of now. Essentially we take every 64 kb of your file and encrypt it with AES-256 encryption algorithm with GCM authentication using your VyomKey as the encryption key. We haven't rolled out any new encryption algo. This is just a start, will add more pages as we go forward. Our main USP is that we use an encryption key of user's own choice - the VyomKey - to encrypt the files which is not there in any other competing product.
Also it's missing a 'Terms of Service' 'Privacy Policy' 'Business Agreement' or 'DMCA Policy' pages. Not very trustworthy, if you don't know where your 'encrypted' data sits.
I would recommend to look at ProtoMail.com.
They provide a lot of transparency, even open-sourced there protocol.
If you want Users to trust their data, your Server, you'll have to provide more than a 'good encryption'.