Technology is disclosed herein for sharing encrypted data within a client-server distributed data storage system. According to at least one embodiment, a first computing device encrypts multiple data sets of the first computing device using symmetric encryption keys. Each of the data sets is encrypted using a different symmetric encryption key among the symmetric encryption keys. The first computing device shares the encrypted data sets with a second computing device. The first computing device further sends the symmetric encryption keys to the second computing device via a secured channel. The symmetric encryption keys are suitable for decrypting the encrypted data sets at the second computing device. The secured channel is through a server connected with the first and second computing devices. The server cannot access the contents of the secured channel and cannot access contents of the encrypted data sets.