An Experimentally Validated Feasible Quantum Protocol for Identity-Based Signature with Application to Secure Email Communication

Digital signatures are one of the simplest cryptographic building blocks that provide appealing security characteristics such as authenticity, unforgeability, and undeniability. In 1984, Shamir developed the first Identity-based signature (IBS) to simplify public key infrastructure and circumvent the need for certificates. It makes the process uncomplicated by enabling users to verify digital signatures using only the identifiers of signers, such as email, phone number, etc. Nearly all existing IBS protocols rely on several theoretical assumption-based hard problems. Unfortunately, these hard problems are unsafe and pose a hazard in the quantum realm. Thus, designing IBS algorithms that can withstand quantum attacks and ensure long-term security is an important direction for future research. Quantum cryptography (QC) is one such approach. In this paper, we propose an IBS based on QC. Our scheme's security is based on the laws of quantum mechanics. It thereby achieves long-term security and provides resistance against quantum attacks. We verify the proposed design's correctness and feasibility by simulating it in a prototype quantum device and the IBM Qiskit quantum simulator. The implementation code in qiskit with Jupyternotebook is provided in the Annexure. Moreover, we discuss the application of our design in secure email communication

Quantum Secure Privacy Preserving Technique to Obtain the Intersection of Two Datasets for Contact Tracing

Contact tracing has emerged as a powerful and effective measure to curb the spread of contagious diseases. It is a robust tool, but on the downside, it possesses a risk of privacy violations as contact tracing requires gathering a lot of personal information. So there is a need for a cryptographic primitive that obfuscate the personal data of the user. Taking everything into account, private set intersection seems to be the natural choice to address the problem. Nearly all of the existing PSI protocols are relying on the number theoretic assumption based hard problems. However, these problems are not secure in quantum domain. As a consequence, it becomes essential to designing PSI that can resist quantum attack and provide long-term security. One may apply quantum cryptography to develop such PSI protocol. This paper deals with the design of PSI using quantum cryptography (QC), where the security depends on the principles of basic quantum mechanics. Our scheme achieves long-term security and remains secure against quantum attacks due to the use of QC. As opposed to the existing quantum PSI protocols, the communication and computation costs of our scheme are independent of the size of universal set. In particular, the proposed protocol achieves optimal communication and computation costs in the domain of quantum PSI. Moreover, we require only single photon quantum resources and simple single-particle projective measurements, unlike most of the existing quantum PSI protocols

Quantum Secure Threshold Private Set Intersection Protocol for IoT-Enabled Privacy Preserving Ride-Sharing Application

The Internet of Things (IoT)-enabled ride sharing is one of the most transforming and innovative technologies in the transportation industry. It has myriads of advantages, but with increasing demands there are security concerns as well. Traditionally, cryptographic methods are used to address the security and privacy concerns in a ride sharing system. Unfortunately, due to the emergence of quantum algorithms, these cryptographic protocols may not remain secure. Hence, there is a necessity for privacy-preserving ride sharing protocols which can resist various attacks against quantum computers. In the domain of privacy preserving ride sharing, a threshold private set intersection (TPSI) can be adopted as a viable solution because it enables the users to determine the intersection of private data sets if the set intersection cardinality is greater than or equal to a threshold value. Although TPSI can help to alleviate privacy concerns, none of the existing TPSI is quantum secure. Furthermore, the existing TPSI faces the issue of long-term security. In contrast to classical and post quantum cryptography, quantum cryptography (QC) provides a more robust solution, where QC is based on the postulates of quantum physics (e.g., Heisenberg uncertainty principle, no cloning theorem, etc.) and it can handle the prevailing issues of quantum threat and long-term security. Herein, we propose the first QC based TPSI protocol which has a direct application in privacy preserving ride sharing. Due to the use of QC, our IoT-enabled ride sharing scheme remains quantum secure and achieves long-term security as well

Study of serum electrolytes and minerals in hypothyroidism

Background of the study: Hypothyroidism is known to affect electrolyte, fat, protein and carbohydrate metabolism. Though the effects of thyroid hormones on lipid profile has been well established, the effects on electrolytes and certain minerals like calcium, magnesium and phosphorus is not clear and the underlying mechanisms responsible for these changes are not well understood. Aim and objectives: The objective was to find out the effects of hypothyroidism on certain electrolytes and minerals levels. Materials and methods: The study was carried out in Dept. of Physiology in collaboration with Medicine, Endocrinology and Biochemistry.100 cases of overt hypothyroidism of both genders aged 25-60 years were chosen,100 age and sex matched healthy controls were chosen. Blood samples were collected from them and serum TSH, total T3, T4, sodium, potassium, calcium, magnesium and phosphorus levels were measured. The values of the above parameters of cases and controls were compared and statistical analysis was made. Results: It was found that the levels of serum sodium, potassium and calcium were significantly decreased in cases than the controls. Serum magnesium and phosphorus were significantly elevated in cases than controls. Conclusion: From this study we were able to conclude that higher the TSH levels, higher will be serum magnesium and phosphorus in the blood and lower will be serum sodium, potassium and calcium levels