The Agent scans every file and grabs block level changes only. It then compresses the data and encrypts it. It is then transmitted via SSL in-flight encryption. Once it is to the EVault cloud, the data is deduplicated again and protected with at-rest encryption.
This slide provides an animated view of how delta-pro works together with other functions like compression and encryption in the whole backup process:
The agent will monitor the data in the server to be backed up for changes. It will use the filesystem to do a quick-scan to see which files have been modified. For the modified files, the agent will do a next level scan to check for modified blocks. These blocks will then go through a de-duplication process to remove duplications.
The gathered blocks goes through encryption process (a variety of encryption model is provided with the highest level at 256 bit AES Encryption) and compressed. Compression ratio varies and can range from a minimal of 10% for media files (JPEG/MPEG which is already heavily compressed) to 50% for filesystems to 60% for VM and 70-80% for databases.
The compressed and encrypted data are then encrypted again through SSL for transmission over the network to the vault.
At the vault, the data goes through another round of de-duplication to checked against duplication against the previous backed up data and any duplications are removed.
The data safe-set then sits in the vault and it remains encrypted while it is in the vault. This dataset only gets encrypted by the agent when it is restored back to the server.