Security and privacy issues in medical Wireless Body Area Networks (WBANs) constitute a major unsolved concern because of the challenges posed by the scarcity of resources in WBAN devices and the usability restrictions imposed by the healthcare domain. In this talk, a recent published proposal for WBAN architecture based on the well-known publish-subscribe paradigm is presented. On this architecture, sensors are able to encrypt and decrypt personal data using both private cryptography and Attribute Based Encryption (ABE) and thus guarantee confidentiality and fine-grained access control.