> For the complete documentation index, see [llms.txt](https://docs.transferchain.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.transferchain.io/core-concepts/secure-messaging.md). # Secure Messaging This system covers secure messaging protocol and satisfies the following security properties; ### Correctness If no attacker interferes with the transmission, Bob outputs the messages sent by Alice in the correct order and vice versa. ### Immediate decryption and message-loss resilience (MLR) Messages must be decrypted as soon as they arrive. If a message is lost, the parties do not delay and waste time. ### Authenticity While the parties' states are uncompromised (i.e., unknown to the attacker), the attacker cannot change the messages sent by them or inject new ones. Privacy: While the parties' states are uncompromised, an attacker cannot obtain any information about the messages sent. ### Forward secrecy (FS) All messages sent and received prior to a state compromise of either party (or both) remain hidden from an attacker. Post-compromise security (PCS) (aka channel healing): If the attacker remains passive (i.e., does not inject any corrupt messages), the parties recover from a state compromise (assuming each has access to fresh randomness). ### Randomness leakage/failures While the parties' states are uncompromised, all the security properties above except PCS hold even if the attacker completely controls the parties' local randomness. That is, good randomness is only required for PCS. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## 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, and the optional `goal` query parameter: ``` GET https://docs.transferchain.io/core-concepts/secure-messaging.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. 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.