A communication protocol is provided for processes to send and receive arbitrary data in a concurrent computing environment. The communication protocol enables a process to send or receive arbitrary data without a user or programmer specifying the attributes of the arbitrary data. The communication protocol automatically determines the attributes of the arbitrary data, for example, the type and/or size of the data and sends information on the attributes of the data to a process to which the data is to be sent. Based on the information on the attributes of the data, the receiving process can allocate appropriate memory space for the data to be received.