A major security vulnerability in the mobile telecommunication network is that wireline signaling messages are cleartext. The latest protocol for wireline signaling message security is Mobile Application Part Security (MAPSec), which protects MAP (a signaling message protocol) messages on the link between nodes. MAPSec is a limited solution because it still leaves MAP signaling messages unsecured in intermediate nodes, and also leaves other wireline signaling message protocols unsecured both on the link and in intermediate nodes. Hence, there is a need for a more comprehensive wireline security scheme to protect all types of wireline signaling messages end-to-end i.e., both on the link and in intermediate nodes. As a solution, we propose EndSec, an end-to-end wireline signaling message security protocol for all types of signaling messages. EndSec works by inserting cryptographic checks on data items in signaling messages, has capabilities to self-detect and repair corruption, and identifies the nodes causing corruption.