This paper summarizes our work on group communication in a fully asynchronous Byzantine environment. Instead of failure detectors or timing information, our protocols use randomization to circumvent the impossibility result by Fischer, Lynch and Paterson. This is the first time this technique is used for a real system; thanks to modern cryptography, our protocols are practical and fast enough to be used in practice. To cleanly combine cryptography with fault tolerance, a new model had to be developed that might be of independent interest.