Data privacy management, cryptocurrencies and blockchain technology ESORICS 2021 international workshops, DPM 2021 and CBT 2021, Darmstadt, Germany, October 8, 2021, revised selected papers - Garcia-Alfaro, Joaquin; Muñoz-Tapia, Jose Luis; Navarro-Arribas, Guillermo; Soriano, Miguel (Springer, 2022)