I have been testing a site which has End to End Encryption of one's files before they are uploaded to the site. The site is called Tresorit and the link is at
You can place a password on the link that you will send to the party on the other end and files can be set to expire in the number of days that you determine. There is a 5gb limit on the number of files that can be uploaded.
Tresorit uses Zero Knowlege authentication, which is explained below.
Zero-knowledge authentication Unlike other services,
Tresorit never transmits or stores files, encryption keys and user
passwords in unencrypted or unhashed form. Due to the strength of
Tresorit’s end-to-end encryption and security, breaking this protection
would take several human lifetimes. This is why we can never recover
forgotten passwords, or hand over your data to law enforcement in case
of a legal inquiry.
So the way it works is that you would select the files to be uploaded, place a password on the files, encrypt the files on your computer before they are uploaded and finally, email the URL link to the person who needs to get the documents. You would either call the person or text the person the password as sending the password via email would not be a secure form of communication.
Please note if there is a Man in the Middle attack on the files, the attacker may be able to capture the URL link, but they would not be able to decrypt the files because they were not given the password to decrypt them. In addition, the files are encrypted using AES 256-Bit, which is used by the military.