What encryption is it?

[radio-link]

When using the XTS5000 in analog conventional mode, equipped with des-xl, can I tell if some unknown stranger on my frequency uses also DES/DS-Xl, just with another key, or is the encryption system not guessable?

When the other one transmits I get the flashing sign like when receiving a message with the proper key, just instead of voice only noise. Can also a DVP or DVI user cause this effect, or does it tell me, that the stranger also uses DES or DES-XL, like me?

[XDCLabs.COM]

In analog mode the radio cannot determine the encryption algorithm being used. So it could be just a different key or a differen flavor of encryption. In digital mode (for IMBE, not VSELP) the algorithm ID is embedded in the voice transmission. However the radio does not forward this info to the user.