  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.
