Bilateral key exchange (BKE) was an encryption scheme utilized by the Society for Worldwide Interbank Financial Telecommunication (SWIFT).
[1] The scheme was retired on January 1, 2009 and has now been replaced by the Relationship Management Application (RMA).
A bilateral key allowed secure communication across the SWIFT Network.
This was normally accomplished by the exchange of various SWIFT messages used specifically for establishing a communicating key pair.
BKE keys were generated either manually inside the SWIFT software, or automatically with the use of a secure card reader (SCR).