Securing Modern API Architectures: From Domain-Driven Design to Advanced Cryptography

Abstract

Application Programming Interfaces (APIs) have evolved into critical enablers of digital transformation, serving as the connective tissue for enterprise systems across industries. As organizations adopt domain-driven API architectures to improve modularity and alignment with business contexts, the security landscape has grown increasingly complex. This article examines the convergence of architectural strategies and advanced security techniques in modern API ecosystems. It explores domain-driven API design principles, API gateway functions, and authentication frameworks, including OAuth 2.0, API key validation, and JWT with digital signatures. The article investigates payload protection strategies, analyzing symmetric encryption, asymmetric cryptography with public-private key pairs, and elliptic curve cryptography for API contexts. Special attention is given to Generative AI APIs, which pose novel security challenges, including safeguarding sensitive prompts, mitigating adversarial manipulation, and enforcing usage compliance. Forward-looking innovations—cryptographic watermarking for AI outputs, zero-trust monitoring frameworks, and quantum-resistant encryption—collectively chart the path toward secure and resilient API infrastructures that balance security requirements with performance considerations and implementation feasibility.