Cryptography – Secure Contract Exchange Protocol
This 2,500-word Cryptography assignment for Coventry University examines the design of a secure communication protocol for the digital exchange and signing of property contracts. The scenario is based on Lauren Order & Cashgrab LLP (LO&C), a UK and overseas property law firm seeking to establish a comprehensive document handling, exchange and signing system that supports remote property transactions while remaining consistent with legal requirements and enforceable under UK law. The assignment requires students to consider the exchange of contracts using the extended CIA model and to devise a secure communication protocol involving three parties: LO&C, the buyer's solicitor Hackit & Run (H&R), and the seller. The scenario specifies that LO&C communicates with the buyer through H&R, that LO&C and the seller collaborate on initial contract drafts, and that LO&C prepares and sends the final contract to the seller for approval and digital signing before forwarding the signed contract to H&R for the buyer's signature. LO&C and H&R have an existing secure communication relationship. A central requirement is the identification and justification of suitable encryption algorithms for the different stages of the contract exchange protocol. Students may select algorithms covered in lectures or undertake additional research to identify alternative algorithms. The report must explain why particular algorithms are appropriate at different stages of the protocol and demonstrate how the selected cryptographic techniques address the practical security requirements of the scenario. The protocol must be clearly illustrated using suitable graphics and pseudocode, with functioning code being an optional higher-level approach. Students are required to identify the strengths and limitations of their proposed protocol and discuss their findings. The assignment therefore combines theoretical knowledge of modern cryptography with practical protocol design and evaluation. Generative AI may be used to create suitable code where permitted, but students must demonstrate their understanding of the code. The assessed learning outcomes cover modern cryptographic concepts and techniques, including symmetric-key cryptography, key exchange, asymmetric cryptography, digital signatures, digital certificates and authentication. Students are also expected to model, test and assess the suitability of cryptographic protocols and algorithms for practical requirements and critically evaluate current research and technological developments in cryptography and its applications.
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