Posted on October 11th, 2013 in Amazon S3, Azure Blob Storage, BaseCamp, Box.net, Cloud Appliance, Cloud Computing Use Cases, cloud file server, Cloud Governance, Cloud Security, Copy.com, DropBox, Dump Truck, Google Docs, Google Drive, Google Sites, Google Storage, HP Object Storage, iCloud, Object Storage, OpenStack, Private Cloud, RackSpace Cloud Files, Scality, Storage Made Easy, SugarSync, UbuntuOne, Zimbra Cloud | 1 Comment »
The recent PRISM Data snooping controversies have heightened almost every companies awareness of the potential vulnerabilities of data stored off-premise in the Cloud. Many Cloud Storage companies talk about encrypting data ‘at rest’ but the real issue is that the storage companies control the encryption rather than the company whose data is stored controlling the private key.
Amongst many other, one of the services that the Storage Made Easy Cloud service provides is an encryption service that can encrypt data uploaded to remote Cloud Storage. As SME supports around 45 cloud storage vendors this means that all of these are able to take advantage of private key encryption for some or all data. This private key is not stored by Storage Made Easy. If you lose it, or forget it, you cannot get access to your data.
SME uses AES-256 encryption using the Rijndael cipher, with Cipher Block Chaining (CBC) where the block size is 16 bytes. The cipher Rijndael consists of:
- an initial Round Key addition
- a final round.
The chaining variable goes into the “input” and the message block goes into the “Cipher Key. The likelihood of recovering a file that has been encrypted using our encryption is fairly remote. The most efficient key-recovery attack for Rijndael is exhaustive key search. The expected effort of exhaustive key search depends on the length of the Cipher Key and for a 16-byte key, 2127 applications of Rijndael.
Once files are encrypted in this manner they can be accessed by an of the comprehensive SME desktop (Mac, Windows, Linux) or mobile tools (Windows Phone, iOS, Android, BlackBerry). When an encrypted file is accessed the user is prompted to provide the private key phrase before the file can be opened.
Any AES-256 decryption tool that supports the Rijndael cipher with 16 byte blocksizes can be used to un-encrypt files. For example the popular freeware file manager Total Commander has a free plugin to handle such decryption.
Standalone desktop decryption tools are also provided by Storage Made EAsy in the event encrypted files are downloaded direct from remote clouds rather than via the SME service. These tools enable the desktop decryption of files using the private key that was set on upload. These Apps are available for Mac, Windows and Linux Operating Systems from the SME Cloud Tools page.
What we have outlined so far is with regards to the Storage Made Easy SaaS hosted service but SME also provides this service as an on-premise Cloud Control service that can reside behind the corporate firewall. It enables the ability to keep very sensitive data behind the corporate firewall but still enable secure file sharing and at the same time offers the ability to encrypt data that is stored on remote cloud storage and other SaaS services.