# A Review of Blockchain Technology Applications in Ambient Assisted Living
## 3 Results
### Security and Privacy
Some experimental findings and confidentiality proofs that demonstrate a particular suggested protocol that has a reasonable computational cost, as well as security safeguards for digital healthcare transactions, are presented in [45]. For decentralized and trustworthy healthcare data interactions, smart contracts and Elliptic Curve Encryption can be employed. One goal of ambient assisted living data protection protocol is to be resistant to a variety of threats and to have reasonable operating and computing capabilities [15]. A blockchain solution using a zero-knowledge-based authentication architecture to tackle privacy issues is presented in [29]. The architecture authenticates devices without revealing any information about the identity of the user. The paper also introduces the ZKNimble cipher, which is suitable to be used by devices that do not benefit from a good processing power. According to [27], the ambient assisted living and care systems should deliver and share patient data through a secure transfer to ensure the confidentiality of data [93]. This was made feasible using a blockchain-based approach to the system's architectural design [55], while work still needs to be carried out on interoperability. It is explained in [20] how many IoT applications in healthcare are no different from those in any other area, and the research should concentrate on the industry's unique requirements, such as good levels of privacy and security. In this context, the number of blockchain-based applications in healthcare has increased lately, but the domain highly demands interdisciplinary studies [30]. A blockchain classification for IoT applications is provided in [47]. The authors explore the most prevalent blockchain systems for healthcare. In [50], a blockchain-based solution is proposed for managing private data using Hyperledger Fabric and Caliper and can be used in various domains such as healthcare. The core benefits of blockchain technology for such systems are immutability, traceability, and transparency [80]. In [22], a decentralized and scalable architecture is presented supporting device access, authentication, as well as data security. A novel authentication protocol has been devised and constructed on Physical Unclonable Functions cryptographic primitives. This makes it practically difficult to predict the key values of the protocol because of the randomness provided by the physical architecture of the protocol. The system suggested in [53] enables medical officials to authenticate data received by a common wearable device with a verification error of less than 1% and a price compared with fewer as being much cheaper for one hour of observing the activity. A decentralized specific ring-based authorization method, as well as an authentication scheme and patient's records anonymity algorithms, are provided to increase the proposed system's security [58]. It allows for decentralized automated identity management, privacy, and security [61]. Finally, in [15], the authors use blockchain to protect patients' anonymity and privacy from several potential threats while enabling important institutions to interact with one another. Only authorized users have access to the genuine identities, addresses, as well as medical data of patientsin the proposed system [101]. Authorities should use blockchain to tackle the issue of cyber-attacks tampering with sensor data [56].