Hyunsung Kim

An efficient privacy-preserving authentication scheme with adaptive key evolution in remote health monitoring system

The remote health monitoring system enables a doctor to diagnose and monitor health problems anywhere for a patient. However, since the patient health information is very sensitive and the Internet is unsecure and prone to many attacks, data can be easily compromised by adversaries. Worse, the mobile phone is also easy to be compromised. Clearly, these issues have brought different privacy and security requirements in wireless healthcare. To address these challenging issues, in this paper, we propose an efficient privacy-preserving authentication scheme with adaptive key evolution, which can prevent illegal access to the patient’s vital signs. Furthermore, we model the leakage process of the key information to set proper key renewal interval, which can adaptively control the key evolution to balance the trade-off between the communication efficiency and security level. The security analysis demonstrates that our scheme can achieve authenticated key agreement, perfect and strong key insulation, privacy preservation, and other important security goals, e.g. authenticity, integrity and freshness of transmitted messages. The performance evaluation shows that our scheme is computationally efficient for the typical mobile phone with limited resources, and it has low communication overhead.

Identity-Based Privacy Preservation Framework over u-Healthcare System

The digitization of patient health information has brought many benefits and challenges for both the patient and doctor. But security and privacy preservation have remained important challenges for wireless health monitoring systems. Such concerns may result in reluctance and skepticism towards health systems by patients. The reason for this skepticism is mainly attributed to the lack of assurances about the way patient health information is handled and the implications that may result from it on patients’ privacy. This paper proposes an identity-based privacy preservation framework over u-healthcare systems. Our framework is based on the concepts of identity-based cryptography and non-interactive key agreement scheme using bilinear pairing. The proposed framework achieves authentication, patient anonymity, un-traceability, patient data privacy and session key secrecy, and resistance against impersonation and replay attacks.

A Pairing-Free Public Key Encryption with Keyword Searching for Cloud Storage Services

Although cloud computing provides a platform for numerous adorable applications, users are still detracts from fully utilizing its services, for fear of jeopardizing data confidentiality and privacy by surrendering maintenance and management roles in the hands of cloud service providers (CSPs). A natural resolution to users’ concern is employing cryptographic measures which allow searching for a particular keyword flexibly stored in the cloud without divulging data privacy to any unwanted party even the CSP itself. Already there has been many keyword searchable encryption researches done, but they mostly bear a weakness of offline keyword guessing attack, besides they are based on the heavier pairing computation. We therefore devise an efficient public key encryption with keyword search (PEKS) protocol that is pairing-free and is resilient against offline keyword guessing attack for cloud storage services. Our basic construction is based on the Diffie-Hellman problem and the El Gamal encryption scheme to achieve a secure channel-free public key encryption with keyword searching (SCF-PEKS). In this design a user sends a key allowing the CSP to only identify words containing a specific keyword and return search results and learn nothing else besides.

Three Factor Authentication Protocol Based on Bilinear Pairing

Secure authentication mechanism is a pre-requisite to remote access of server’s resources particularly when done over the Internet. This paper presents a three factor authentication protocol which is based on verification of user’s: biometrics, knowledge proof of a password and possession of token to pass authentication. The proposed protocol utilizes bilinear mapping for session key establishment and elliptic curve discrete logarithm problem for security.

Freshness Preserving Hierarchical Key Agreement Protocol Over Hierarchical MANETs

Recently, Guo et al. proposed an efficient and non-interactive hierarchical key agreement protocol applicable to mobile ad-hoc networks, which is a try to solve the open question: How can secrets be established if an adversary can eavesdrop on every message exchange? However, their protocol does not support freshness of the established session key that key agreement protocols should have. Thereby, we propose a freshness preserving hierarchical key agreement protocol over the hierarchical MANETs. Compared with other existing protocols, the proposed protocol offers much better performance on the bandwidth consumption, the computational cost, and the storage cost.

A Pairing Based Authentication and Key Establishment Scheme for Remote Patient Monitoring Systems

With the evolution of Wireless Medical Sensor Networks (WMSNs), real-time remote patient monitoring has become more feasible than ever before. Different sensors can be used e.g. at home to monitor patient’s vital signs such as pulse, respiration and blood pressure. However, given the distributed nature of WMSNs for remote patient monitoring, there is a greater challenge in ensuring data security, integrity, confidentiality and access control. This is because the transmission of personal and medical information is done over insecure communication channels i.e. the Internet. At the same time, patient’s physiological data are highly sensitive and remote patient monitoring systems are extremely vulnerable to many attacks. Since there is great need to access the real-time data inside WMSN nodes, proper authentication of entities (e.g. health personnel) must be ensured before allowing them access. To this end, this paper proposes a pairing based authentication and key establishment scheme for remote patient monitoring systems. The scheme is two-factor i.e. combines smartcard and password, and achieves various desirable properties such as mutual authentication, strong access control, patient identity privacy, patient un-traceability, replay attack resistance and forward secrecy.

Attack on Recent Homomorphic Encryption Scheme over Integers

At CDCIEM 2012, Yang et al. proposed a new construction of somewhat homomorphic encryption scheme over integers, which is quite efficient in the perspective of the key size. In this paper, we present an effective lattice reduction attack on Yang et al.’s scheme, where it is easy to recover the plaintext by applying LLL algorithm.