Abstract: A system, computer readable medium and a method for encrypting a file, the method may include retrieving the file from a storage service; segmenting the file into multiple file segments; calculating a file segment signature for each of the multiple file segments to provide multiple file segment signatures; encrypting each of the multiple file segments to provide multiple encrypted file segments by using encryption keys that are in response to the multiple file segment signatures; wherein the multiple encrypted file segments form an encrypted file; and sending the multiple encrypted file segments to the storage service.

Abstract: A method for file management, the method may include: calculating, by a management server that is located within a cloud computing environment, signatures of multiple files that are stored at multiple storage entities; and finding, by the management server, groups of similar files out of the multiple files, wherein the finding is in response to similarities between signatures of the multiple files; wherein the multiple storage entities comprise at least a first storage entity that is managed by a first management entity and a second storage entity that is managed by a second management entity that differs from the first management entity.

Abstract: System, computer readable medium and method for decryption. The method may include receiving, by a third computerized system and from a fourth computerized system, a first encrypted file entity key and signed access metadata. The first encrypted file entity key is created by encrypting a file entity key by a first computerized system using an encryption key of a second computerized system. The signed access metadata is signed by the file entity key. The encrypted file entity is created by encrypting a file entity by the first computerized system using the file entity key. Sending, by the third computerized system, the signed access metadata and the first encrypted file entity key to the second computerized system. Receiving a response from the second computerized system. Determining, based on the response from the second computerized system, whether to facilitate a decryption of the encrypted file entity by the fourth computerized entity.

Abstract: A method for managing a virtual distributed file system includes maintaining by a master device located in a cloud computing environment, a metadata data structure that stores metadata about locations of most updated versions of multiple file portions and security levels of the file portions, at least one file portion being stored at a user device coupled to the cloud computing environment, and maintaining by the master device, transaction of file portions to user entities, at least one user entity being hosted by the user device, based on at least metadata stored in the metadata data structure about the file portions.