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Access control plays a crucial role in providing security and privacy in e-Health systems. Attribute-Based Access Control (ABAC) is a fine-grained, dynamic access control model that has several advantages over the traditional access control models. ABAC works based on the attributes of the subject, object, action, and environment and is supposed to be the best fit for distributed environments. However, as the mismatch between attributes in a distributed environment like the e-Health domain is inevitable, ABAC is augmented with semantic technologies, forming Semantic Attribute-Based Access Control (SABAC), to take into account the semantic relationships between attributes. Hitherto, a considerable number of SABAC schemes have been proposed for different contexts. This dissertation performs a systematic literature review on the existing SABAC schemes to identify different strategies for developing SABAC as well as open problems towards an ideal SABAC. One of the main problems of the access control systems is the fact that they rely on a trusted reference monitor that not only can be easily bypassed, e.g., by direct access to the data, but also restricts the scalability, as it should always be online. This issue is addressed by proposing a cryptographic counterpart for access control systems, e.g., Attribute-Based Encryption (ABE) for ABAC. However, there is a lack of a cryptographic counterpart for SABAC. Hence, this dissertation proposes the first Semantic Attribute-Based Encryption (SABE) framework through the combination of ABE schemes and semantic technologies. The proposed SABE framework is developed based on two different schemes namely, Semantically-Enriched Key (SEK) and Semantically-Enriched Access Structure (SEAS). Although SABE can be considered as a cryptographic SABAC, obligations as an important feature of ABAC are missing in ABE (and accordingly SABE) schemes. Obligations are meant to enforce extra constraints that cannot be addressed using normal access control policies. Hence, this dissertation extends ABE schemes with enforceable obligations based on the trusted hardware enclaves provided by Intel Software Guard Extensions (SGX) to form an Attribute-Based Encryption with enforceable OBligations (OB-ABE) scheme. The dissertation also proposes a formal language for the specification of enforceable obligations in OB-ABE. The proposed SABE-SEK, SABE-SEAS, and OB-ABE schemes are implemented to evaluate their performances compared to the conventional ABE schemes. The security of the proposed schemes is also formally verified using the widely accepted formal verification methods and tools. Another issue with ABAC and SABAC is the lack of a formal mechanism for analyzing access control policies when authoring or integrating them. ABACbased systems basically address the inconsistencies between access control policies at runtime (when making a decision) based on some combining algorithms provided by the XACML standard. However, runtime conflict resolution negatively affects the performance of the access control system. There are also other properties for the access control policies that need to be analyzed. Therefore, this dissertation proposes an approach to analyze the access control policies using a process algebra, called mCRL2. The proposed approach analyzes the completeness, consistency, and safety of the access control policies before their deployment.