I don't read the Liberty BASIC or Just BASIC forums any more (and haven't done for several months) but a kind person alerted me to this comment recently posted at the LB forum: "The .tkn is your .bas program compiled to Smalltalk". This was posted by somebody who knows perfectly well that it isn't true, but seems to have no scruples about deliberately misleading a self-confessed 'newbie'.
In fact, as has been known for a long time, the TKN file contains the original BASIC program with only trivial modifications: for example comments are deleted and keywords are converted to capitals. This isn't immediately obvious by examining the file, because the resulting program is minimally encrypted (using something very similar to the Caesar Cipher you were taught at school), but the encryption is easily reversed so that you can see exactly what the file contains.
LBB can decrypt any TKN file created by a registered copy of Liberty BASIC; simply select the TKN file in the 'Load Liberty BASIC program' dialog (change the filter to 'All Files' to make this easier). To prevent abuse of this feature LBB requests the User Name and Registration Key of the user who created the TKN file, although it must be emphasised that decryption does not depend on this information and LBB could decrypt any TKN file without it.
Being able to recover the original BASIC program (less comments) from a TKN file can be a godsend if somebody has lost the original .BAS file, but it does mean that 'compiled' Liberty BASIC applications (which necessarily include the TKN file) are vulnerable to reverse-engineering, and any code 'secrets' can easily be discovered.