# Trust Service Providers A **Trust Service Provider (TSP)** ensures security, authenticity, and legal validity in digital transactions. Key functions: * Issue/manage digital certificates * Provide timestamping services * Validate signatures for authenticity and integrity * Secure storage of signed documents * Detect tampering after signing **Regional regulation examples:** * India – licensed under the IT Act * EU – regulated by eIDAS **Prominent TSPs:** eMudhra, DigiCert, GlobalSign, Entrust. --- # 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://support.emsigner.com/key-concepts/trust-service-providers.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.