A system and method for a secure key exchange between two trains operating within a track network may include generating a first or second public key based on a secret random number, generating a shared secret key based on the first or second public key, authenticating one or more key exchange communications by a remote server based on a digital signature established with an on-board key associated with the first train, authenticating a communication by a remote server based on the digital signature of the second train signed with an on-board key associated with the second train, and establishing secure train-to-train communication between the two trains by generating a shared secret key based on a public key received from the other train, the secure key exchange protecting the two trains from a man-in-the-middle attack.