Disclosed is a system and method to create an encrypted file system on a block chain. The system creates the block chain controlling an access to the encrypted file system. The block chain defines a user permission to access at least a portion of the encrypted file system. The system creates the encrypted file system by recording a unique file ID in the block chain, where the unique file ID stores a chunk index including memory locations of multiple chunks storing portions of a file in the encrypted file system. The system encrypts the file using a channel session key and a file encryption key. The channel session key includes a cryptographic key computed based on information known to users granted at least a temporary access to the file, and the file encryption key includes a cryptographic key used to encrypt each file in the encrypted file system.