The deployment of massive multiple-input multiple-output (MIMO) is considered one of the key technologies that will allow next-generation wireless networks to reach the capacity and energy efficiency demands of future 5G mobile systems. In addition to the capacity and energy efficiency requirements, the issue of information secrecy is also seen as a main research topic that must be addressed in the context of massive MIMO. Recently, the exploration of the physical layer characteristics of the wireless channel is being object of intensive research in order to develop advanced secrecy schemes that can protect information against eavesdropping attacks. Following this line of work, in this manuscript we consider a massive MIMO system and jointly design the channel precoder and security scheme. By doing that we ensure that the precoding operation does not reduce the degree of secrecy provided by the security scheme. The fundamental working principle of the proposed technique is to apply selective random rotations in the transmitted signal at the antenna level in order to achieve a compromise between legitimate and eavesdropper channel capacities. These rotations use the phase of the reciprocal wireless channel as a common random source between the transmitter and the intended receiver. To assess the security performance, the proposed joint scheme is compared with a recently proposed approach for massive MIMO systems. The results show that with the proposed joint design, the number of antenna elements do not influence the eavesdropper channel capacity, which is proved to be equal to zero, in contrast to previous approaches.