The construction of a cryptographic protocol to maintain confidentiality when storing multi-owner data requires the combination of two technologies: access control and cryptography. This paper is a literature research about the latter: How can data be encrypted so that multiple receivers can decrypt it. Depending on how the set of receiving users is defined (explicitly or implicitly), different encryption techniques need to be considered. Explicit user definition refers to the notation of broadcast encryption (BE), which again can be implemented based on various technologies. Implicit user definition can be achieved with classical attribute-based encryption (ABE). This literature review introduces and evaluates currently proposed approaches to implement these protocols. It is intended to provide an introduction into the topic and its related challenges. It also aims to support the decision of protocol designers: Which technology to choose for a practical application? Therefore, this paper elaborates a decision tree.     «

The construction of a cryptographic protocol to maintain confidentiality when storing multi-owner data requires the combination of two technologies: access control and cryptography. This paper is a literature research about the latter: How can data be encrypted so that multiple receivers can decrypt it. Depending on how the set of receiving users is defined (explicitly or implicitly), different encryption techniques need to be considered. Explicit user definition refers to the notation of broadc...     »