Public procurement is one of the government activities most prone to corruption, and e-procurement systems have been recommended to increase transparency, outreach, and competition. Other benefits include ease of access to public tenders and easier detection of irregularities. One of the main challenges with the existing e-procurement/auction systems is ensuring bid privacy of the losing bidders and collusion between bidders and auctioneer. Most of the auction systems, proposed, depend either upon auctioneer(s) or on the trusted third party, which, according to us, is the biggest problem for addressing corruption. We propose a blockchain-based solution for Public Procurement, which eliminates auctioneers/third-parties using secure multi-party computation (MPC). Our solution fully preserves bid privacy and is secure against malicious bidders.
In recent times, many blockchain solutions have been proposed for automatic electronic contracts on a blockchain. The most prominent example of it is Ethereum smart contracts. In many cases, it is necessary to be able to sign contracts involving things in the physical world that are not represented in the form of crypto-assets. Such a contract can be legally enforced after all the parties have signed them in case any party backs out after signing the contract. We propose a solution to advertise and sign anonymous multi-party contracts that are designed to be acceptable and enforceable in a court of law once they are signed. To enable this, we also provide a designated deanonymizer ring signature that allows some designated deanonymizers to be able to break the anonymity of the signer and also allows them to prove the true identity of the signer to any third party of their choice.
Tor, aka ‘The Onion Router’, is a protocol that allows anonymous browsing of the web in the sense that the network address of the client is not known to a single relay or even relays provided by the same provider. The relay that knows the target does not know the source and vice versa. However, the current Tor relays are voluntary and unpaid, doing a social service to protect the identities of people who want to stay anonymous while browsing the web. We propose a modification of the Tor protocol so that the client can anonymously pay the Tor relays for their services through a smart-contract enabled cryptocurrency. Our design ensures that the Tor relays cannot be paid unless the client gets the data and that the client cannot get the data without paying the Tor relays.
We discussed Blockchain-enabled IoT edge computing in the earlier publication of this series, which allows any compute resource owner to join the ecosystem and lend out computer resources required for edge computing/analytics. This paper lists a possible set of challenges implementing the above solution. The primary challenges are ensuring data privacy for the input data files and ensuring computation integrity when executing the computation remotely. The paper talks about current state research and possible practical implementation to address the privacy and integrity challenges using a hardware-assisted trusted executing environment primarily Intel SGX. The paper proposes using unidirectional payment channels to address payment-related challenges.
Recently, the privacy of blockchain transactions has taken center stage. Privacy is an essential feature of crypto-transactions. We have seen privacy-preserving cryptocurrencies like Monero with Cryptonote protocol and Zerocash with Zk-SNARKs. However, the privacy of transactions comes at the cost of the transactions not being visible at all to any regulatory bodies. In most developed or developing countries, the Government is democratic, and it is generally a good idea for the Government to be able to prevent illicit activities like foreign exchange frauds, black markets, criminal funding, and drug trafficking. The XAND blockchain aims to resolve this problem by allowing some authorized participants to view the transactions, while at the same time maintaining the privacy of the transactions from other regular users, including the validators.
Blockchain technology has found application outside of cryptocurrency in recent times. The development of patient-centric storage of medical records on a blockchain has recently gained momentum. However, there have been few developments in providing a solution towards giving up full control to the public so that the concentration of power by only a small group of validators can be avoided. In this paper, we discuss a solution that enables patient-driven interoperability of medical records on a public blockchain while maintaining privacy using new cryptographic constructs and truly giving up control to the general public.
The number of internet-connected devices is increasing as IoT is getting more prevalent. The volume of data collected by IoT sensors is very high and requires considerable resources for data processing like analytics. Edge processing enables getting the sensor data processed closer to the source. This paper proposes the use of blockchain-based decentralized applications to enable IoT edge processing.