With the rapid development of health equipments, increasingly more patients have installed the implantable medical devices (IMD) in their bodies for diagnostic, monitoring, and therapeutic purposes. IMDs are extremely limited in computation power and battery capacity. Meanwhile, IMDs have to communicate with an external programmer device (i.e., IMD programmer) through the wireless channel, which put them under the risk of unauthorized access and malicious wireless attacks. In this paper, we propose a proxy-based fine-grained access control scheme for IMDs, which can prolong the IMD's lifetime by delegating the access control computations to the proxy device (e.g., smartphone). In our scheme, the proxy communicates with the IMD programmer through an audio cable, which is resistant to a number of wireless attacks. Additionally, we use the ciphertext-policy attribute-based encryption (CP-ABE) to enforce fine-grained access control. The proposed scheme is implemented on real emulator devices and evaluated through experimental tests. The experiments show that the proposed scheme is lightweight and effective.
By contrast, in the proxy-based architecture, the powerful proxy device handles those resource-consuming tasks. It can support more complicated and robust access control schemes. However, previous proxy-based access control schemes either depend on anomaly detection of the access pattern @cite_41 @cite_35 or only verify the authenticity of the programmer @cite_0 @cite_14 . The former method does not check the access requestor and require a training process for each patient. The second method is vulnerable considering that an attacker could also purchase or steal a legitimate programmer. Our scheme views the programmer and its operator together as one subject, and the access decision is made based on the programmer operator. We not only authenticate the operator, but also employ the CP-ABE algorithm to verify the qualifications of the operator.
@cite_41 @cite_35 @cite_14 @cite_0
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The use of radio for communication with medical devices provides important convenience and safety features. However, devices that respond to unauthorized queries may inadvertently disclose their presence. It is reasonable for users to expect that their devices' detectability by third parties to be limited, and thus even eavesdroppers to an authorized conversation (e.g. a command sent to an insulin pump) should observe an access code of minimal utility for triggering future transmissions. Access rights should be revocable in a manner that limits that harm that can be caused by authorized devices in the possession of unauthorized users. In order to detect inappropriate use, it may be desirable for access history to be available for audit. We describe a family of replay-attack resistant protocols suitable for embedding into query messages that can authorize users with a range of differentiated access rights. Implanted devices utilizing these techniques can evade detection by suppressing responses to queries that do not contain appropriate authorization. Techniques are described that can support revocation of authorization and audits of access history. Finally, we observe that the processing of unauthorized queries consumes power and thus can be used to mount a potentially devastating denial-of-service attack against the batteries of both conventional devices and devices that utilize the cryptographic protocols we describe. Since field-powered communication systems (e.g. HF-RFID) contain embedded general-purpose processors that operate using only power extracted from externally applied fields, they are substantially more robust against such forms of attack. Abstract With the proliferation of smart grids, traditional utilities are struggling to handle the increasing amount of metering data. Outsourcing the metering data to heterogeneous distributed systems has the potential to provide efficient data access and processing. In an untrusted heterogeneous distributed system environment, employing data encryption prior to outsourcing can be an effective way to preserve user privacy. However, how to efficiently query encrypted multidimensional metering data stored in an untrusted heterogeneous distributed system environment remains a research challenge. In this paper, we propose a high performance and privacy-preserving query (P2Q) scheme over encrypted multidimensional big metering data to address this challenge. In the proposed scheme, encrypted metering data are stored in the server of an untrusted heterogeneous distributed system environment. A Locality Sensitive Hashing (LSH) based similarity search approach is then used to realize the similarity query. To demonstrate utility of the proposed LSH-based search approach, we implement a prototype using MapReduce for the Hadoop distributed environment. More specifically, for a given query, the proxy server will return K top similar data object identifiers. An enhanced Ciphertext-Policy Attribute-based Encryption (CP-ABE) policy is then used to control access to the search results. Therefore, only the requester with an authorized query attribute can obtain the correct secret keys to retrieve the metering data. We then prove that the P2Q scheme achieves data confidentiality and preserves the data owner’s privacy in a semi-trusted cloud. In addition, our evaluations demonstrate that the P2Q scheme can significantly reduce response time and provide high search efficiency without compromising on search quality (i.e. suitable for multidimensional big data search in heterogeneous distributed system, such as cloud storage system). Proxy re-encryption (PRE) allows a semi-trusted proxy to convert a ciphertext originally intended for Alice into one encrypting the same plaintext for Bob. The proxy only needs a re-encryption key given by Alice, and cannot learn anything about the plaintext encrypted. This adds flexibility in various applications, such as confidential email, digital right management and distributed storage. In this paper, we study unidirectional PRE, which the re-encryption key only enables delegation in one direction but not the opposite. In PKC 2009, Shao and Cao proposed a unidirectional PRE assuming the random oracle. However, we show that it is vulnerable to chosen-ciphertext attack (CCA). We then propose an efficient unidirectional PRE scheme (without resorting to pairings). We gain high efficiency and CCA-security using the “token-controlled encryption” technique, under the computational Diffie-Hellman assumption, in the random oracle model and a relaxed but reasonable definition. Enforcing in code privacy laws, internal company rules and principles like Privacy by Design is recognized as a challenge for the IT industry. In this paper we analyze the steps required and propose a guide towards this major goal. Our proposal is to emphasize the need to overcome the limits of service orchestration and create strong privacy and security enabling architectures based on two main ideas. The first idea is to use a semantic firewall that is capable to check privacy properties for the communication between applications and cloud and between cloud's sub-systems. The second idea is to improve current SOA architectures with architectures based on executable choreographies that can be formally verified. In this paper we identify three types of executable choreographies. New types of abstraction which machines can verify and humans can trust are enabled by executable choreographies that act like truly verifiable environments for cloud applications.