## 7 Related Works
Although, the authors implemented the ARAN routing protocol in healthcare applications, their study did not show the different effects, e.g., energy consumption, memory requirements, _etc._ Therefore more analysis is needed to implement the secure routing protocols in the real-time healthcare applications. Furthermore, the authors claim that their scheme provides confidentiality, authentication and integrity. [PERSON] [60] proposed a secure health monitoring network against denial-of-service attacks using cognitive intelligence. They proposed energy-efficient cognitive routing protocol that copes with the Sybil and worm-hole attacks for healthcare applications. [PERSON] _et al._[79] proposed a MAACE protocol where an authorized professional can access the patient's data. Their scheme provides mutual authentication and access control, which is based on elliptic curve cryptography (ECC). Furthermore, the authors claim their scheme can defend from real-time attacks, such as replay attacks, and denial-of-service attacks. The MAACE architecture is composed of three layers, namely, a sensor network layer (SN), a coordination network layer (CN), and a data access layer (DA). In this scheme, the SN transmits data to the CN (_i.e._, PDA, laptop or cell phone), later, the data is forwarded to the DA for future records. Although, [PERSON] _et al._'s protocol provides enough security, it is susceptible to information-leakage attacks, which could be dangerous for a patient's privacy. As a result, the patient's vital signs are exposed to unauthorized users, which is not acceptable for real-time healthcare applications. [PERSON] _et al._[83] implemented a secure wireless mode-base medical sensor network for health care applications. Their scheme has three main components: (a) A two tier scheme is used for data authentication based on the patient's biometric and physiological data. (b) An ECC-based secure key exchange protocol is used to set up shared keys between the medical sensor and the base station. (c) A symmetric encryption/decryption algorithm is used for data confidentiality and integrity. Their security mechanism is as follows: each medical mode (Motive T-mote) is connected with a small fingerprint scanner. The patient's identity is verified by the base station via the patient's biometric signature. The query and patient data are encrypted using RC5 block cipher cryptosystem and data integrity is provided by a Hashed message authentication code (H-MAC). An elliptic curve cryptographic (ECC) based key exchange protocol is used between the medical sensor and the base station. Further, the scheme consumes 24.7 KB of ROM and 2.8 KB of RAM, and ECC operation takes 5.3 seconds for key exchange. Their scheme is secure against spoofing and physical compromise of motes, and provides confidentiality, authentication and integrity. [PERSON] [89] proposed a secure mobile healthcare system using a trust-based multicast scheme. A multicast strategy is used that employs trust to evaluate the behavior of each node. By doing so, only trustworthy nodes are permitted to participate in communications, while the misbehavior of malicious nodes identifies them and they are successfully prevented from communicating. The authors have brought forth a new trust evaluation theory whereby a node is only allowed to join the communication initiated by the source node when this new node is trustworthy for the source node. [PERSON] _et al._[90] proposed two key distribution algorithms for enforcing patient privacy in healthcare WSNs through the use of key distribution algorithms. In the first algorithm, a central trusted security server is used to authenticate the participants that belong to the patient group and generate a session key. Four entities are involved in clinical system, namely, patient, clinician, nurse and central authority. In the second algorithm, an independent certificate is used for participant authentication, which is based on public key cryptography.