Abstract

Modern cryptography is at a turning point as digital systems become the foundation of everyday life, business, government, and science. Long-standing security presumptions are called into question by new capabilities and changing threats. The current state of transport security, authentication, and data protection at rest, in transit, and in use is surveyed in this chapter along with key developments, including the standardization of post-quantum cryptography (PQC), “zero trust” architectures, and privacy-enhancing technologies (PETs) like differential privacy, secure multiparty computation, homomorphic encryption, and confidential computing. We extract practical advice on crypto-agility and migration roadmaps while grounding the conversation in current standards and implementations. We wrap off with unresolved issues and potential avenues for further research.