Encryption in transit protects data as it travels between systems, devices and networks by using cryptographic protocols such as TLS (Transport Layer Security) and its predecessor SSL. This prevents eavesdropping, man-in-the-middle attacks and data tampering during transmission, whether the data flows between a user's browser and a web server, between microservices within a data centre or between on-premises systems and cloud environments.
Implementing encryption in transit is a baseline security requirement under virtually all compliance frameworks, including ISO 27001, SOC 2, PCI DSS and the GDPR. Organisations should enforce minimum TLS versions (currently TLS 1.2 or higher), use strong cipher suites, implement certificate management and regularly test their configurations using tools like SSL Labs to ensure that data remains protected during every transmission.