E-transactions systems involve three or more partners in the exchange and sharing of information concerning trades, payments, services and other activities. These include customers communicate through architectures to service providers. We can consider that e-transactions evolve in an area where all these partners collaborate toward achieving similar objectives. As a consequence, this collaboration leads to the creation and modification of messages by each middle agent (as in, for example, transaction amount, consumer name, some public certificates, and so on). The e-transaction process is a complex one because it has, for instance, numerous exchanges between the different partners. There are many applications of e-transactions systems such as e-commerce, e-administration, e-medical, e-science, e-government … Many aspects contribute to the functioning of e-transactions systems such as security aspects (authentication, confidentiality, ...), architecture (such as Cap, 3D secure, ...), privacy of the cyber-consumer, responsibility level of the different partners, benefits of new technologies (mobile, contact-less, biometrics), and many possible application domains. We invite original contributions from researchers in academia, research institutions and industry on these emerging and important areas of information technology. This Workshop on E-Transactions Systems - to be held as part of the 2016 International Conference on Collaboration Technologies and Systems (CTS 2016) - will focus on many topics, some of which are listed below. providing convenience. Broadening to the biomedical field, including biomedical research, collaboration technologies are also used in bioinformatics and life sciences. CoHeB workshop aims at providing a scientific forum for disseminating and discussing the latest advances and research results in the development and/or application of collaboration technologies and systems in healthcare and biomedical fields. The main objective is to bring together researchers, scientists as well as practitioners from academia, industry, government, and research institutions in a multidisciplinary environment where novel ideas and recent achievements can be presented, fostering the creation of new networks and collaborations among ICT researchers and health professionals. The workshop will include a keynote speech, contributed paper sessions and demos, as part of the main CTS2016 Conference.