Eindtoend

Eindtoend, or end-to-end, is a term used in information technology to describe designs or processes that run from one endpoint to another, with essential functions implemented at the endpoints rather than in intermediate layers. The idea is associated with the end-to-end principle, introduced by Saltzer, Reed and Clark in 1984, which argues that certain tasks should be performed only at the endpoints to preserve robustness and simplicity across a network.

End-to-end encryption (E2EE) is a common security application of the term. Data is encrypted on the sender’s device and decrypted only on the recipient’s device, so intermediaries such as servers can access only encrypted content. Keys are typically held by endpoints. E2EE protects content integrity and privacy, but metadata, timing information, and endpoint security remain potential vulnerabilities.

In software engineering, end-to-end testing validates a complete user journey across multiple components or services, from initial input to final output. It aims to ensure that real-world workflows function correctly in an integrated environment, complementing unit and integration tests. End-to-end tests can be time-consuming and sensitive to environment changes.

The term is widely used beyond security and testing to describe any process that spans entire chains from origin to destination. While end-to-end designs can improve coherence and safety, they also introduce challenges such as performance overhead, increased complexity, and potential exposure of metadata if not carefully managed.