Tresorit is a cloud-based, file synchronizing and collaboration solution that enables business users to share confidential data while promosing offline-equivalent security by end-to-en encryption. The software is suitable for making shared directories in a way that the files in the directories are encrypted before uploaded and the encrypted file will get into the cloud. When downloading the file from the cloud it is decryptable only when permitted by the owner. Other users (including Tresorit employees) are unable to decode its contents. The special feature of Tresorit is that the encrypted contents are shareable without re-encryption and that sharing is reversible by permission revocation.