There continues to be a recent push to taking the cryptocurrency based ledger system known as Blockchain and applying its techniques to non-financial applications. One of the main areas for application remains Internet of Things (IoT) as we see many areas of improvement as we move into an age of smart cities. In this paper, we examine an initial look at applying the key aspects of Blockchain to a health application network where patients health data can be used to create alerts important to authenticated healthcare providers in a secure and private manner. This paper also presents the benefits and also practical obstacles of the blockchain-based security approaches in IoT.
Huh @cite_12 propose a novel blockchain PKI management system using Ethereum and smart contracts. The security solution uses RSA public key cryptosystems where public keys are stored in Ethereum and private keys are saved on individual devices. Nevertheless, the presented solution has two problems. The first problem is the long duration time of one transaction (approximately @math seconds). The second problem is a large storage requirement for the constrained Hardware of IoT clients. Solving this problem by a proxy node which should be the third trusted party then decrease the level of security.
@cite_12
2604096638 2797677683 2601330228 2810011639
Since the start of Bitcoin in 2008[1], blockchain technology emerged as the next revolutionary technology. Though blockchain started off as a core technology of Bitcoin, its use cases are expanding to many other areas including finances, Internet of Things (IoT), security and such[2]. Currently, many private and public sectors are diving into the technology[3]. Aside from that, as software and hardware improve, we would see the beginning of IoT. And those IoT devices need to communicate and synchronize with each other. But in situations where more than thousands or tens of thousands of IoT devices connected, we expect that using current model of server-client may have some limitations and issues while in synchronization. So, we propose using blockchain to build IoT system. Using blockchain, we can control and configure IoT devices. We manage keys using RSA public key cryptosystems where public keys are stored in Ethereum and private keys are saved on individual devices. Specifically, we choose Ethereum as our blockchain platform because using its smart contract, we can write our own Turing-complete code to run on top of Ethereum. Thus, we can easily manage configuration of IoT devices and build key management system. Even though we can simply use account as a key management system, which most of blockchain platform supports, we decide to use Ethereum because we can manage the system in a more fine-grained way. For the proof of a concept, we use a few IoT devices instead of a full system of IoT system, which consists of thousands of IoT devices. But in our later study, we would like to build a fully scaled IoT system using blockchain. Traditional PKIs face a well-known vulnerability that caused by compromised Certificate Authorities (CA) issuing bogus certificates. Several solutions like AKI and ARPKI have been proposed to address this vulnerability. However, they require complex interactions and synchronization among related entities, and their security has not been validated with wide deployment. We propose an accountable, flexible and efficient decentralized PKI to achieve the same goal using the blockchain technology of Bitcoin, which has been proven to be secure and reliable. The proposed scheme, called BKI, realizes certificate issuance, update and revocation with transactions on a special blockchain that is managed by multiple trusted maintainers. BKI achieves accountability and is easy to check certificate validity, and it is also more secure than centralized PKIs. Moreover, the certificate status update interval of BKI is in seconds, significantly reducing the vulnerability window. In addition, BKI is more flexible than AKI and ARPKI in that the number of required CAs to issue certificates is tunable for different applications. We analyze BKI’s security and performance, and present details on implementation of BKI. Experiments using Ethereum show that certificate issuance update revocation cost 2.38 ms 2.39 ms 1.59 ms respectively. The Public Key Infrastructure (PKI) in use today on the Internet to secure communications has several drawbacks arising from its centralised and non-transparent design. In the past there has been instances of certificate authorities publishing rogue certificates for targeted attacks, and this has been difficult to immediately detect as certificate authorities are not transparent about the certificates they issue. Furthermore, the centralised selection of trusted certificate authorities by operating system and browser vendors means that it is not practical to untrust certificate authorities that have issued rogue certificates, as this would disrupt the TLS process for many other hosts. SCPKI is an alternative PKI system based on a decentralised and transparent design using a web-of-trust model and a smart contract on the Ethereum blockchain, to make it easily possible for rogue certificates to be detected when they are published. The web-of-trust model is designed such that an entity or authority in the system can verify (or vouch for) fine-grained attributes of another entity's identity (such as company name or domain name), as an alternative to the centralised certificate authority identity verification model. In traditional cloud storage systems, attribute-based encryption (ABE) is regarded as an important technology for solving the problem of data privacy and fine-grained access control. However, in all ABE schemes, the private key generator has the ability to decrypt all data stored in the cloud server, which may bring serious problems such as key abuse and privacy data leakage. Meanwhile, the traditional cloud storage model runs in a centralized storage manner, so single point of failure may leads to the collapse of system. With the development of blockchain technology, decentralized storage mode has entered the public view. The decentralized storage approach can solve the problem of single point of failure in traditional cloud storage systems and enjoy a number of advantages over centralized storage, such as low price and high throughput. In this paper, we study the data storage and sharing scheme for decentralized storage systems and propose a framework that combines the decentralized storage system interplanetary file system, the Ethereum blockchain, and ABE technology. In this framework, the data owner has the ability to distribute secret key for data users and encrypt shared data by specifying access policy, and the scheme achieves fine-grained access control over data. At the same time, based on smart contract on the Ethereum blockchain, the keyword search function on the cipher text of the decentralized storage systems is implemented, which solves the problem that the cloud server may not return all of the results searched or return wrong results in the traditional cloud storage systems. Finally, we simulated the scheme in the Linux system and the Ethereum official test network Rinkeby, and the experimental results show that our scheme is feasible.