# Reliability A zk-rollup in its intended use is a critical piece of financial infrastructure, thus implying stringent requirements in terms of reliability. Reliability is a multi-dimensional concept that can be subdivided into two axes: liveness and fidelity. Liveness means that the system is functioning and responsive to requests and fidelity means that the system is functioning in the intended manner, conforming to the rules or contracts defining its intended behaviour. Together, these two axes capture the concept of reliability, with which the system ensures each of the following outcomes: * Nobody can double spend. * Nobody can spend money that is not theirs. * Valid transactions submitted to the rollup are processed and included in the rollup in a short amount of time. * The prover node network responds in a timely manner to queries for rollup data. * The prover node network responds accurately to queries for rollup data. * The complete rollup data structure is retained. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.orbisprotocol.com/orbis/design-considerations/reliability.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.