ANY CODE BREAKERS HERE?

[BEAST]

These pages are from a notebook that came in a WWII US group. Can someone break the code or at least explain the system to me?

 

Also, it appears that part of the pages were trimmed off. Any idea why?

 

[BEAST]

More pages:

 

[BEAST]

 

[Grant S.]

Not a cryptologist but it looks like the right hand pages are the decoding scheme, and the left hand pages are the messages to be decoded. The proper scheme is chosen by a key, which is not included in the code book but is often based on the time the message is received (like the AKAC-874*). So for example if the message is received at 14 minutes past the hour you go to scheme 14. That's a stupid example but you get the idea. This sort of scheme is for time-sensitive material only as it is fairly easy to crack. The entire book would be replaced regularly. I would also guess that this particular book was used for training. Just has that feel to it.

 

* I may be showing my age here - do we even use this anymore?

[BEAST]

Thanks Grant for your response. The closest experience to decoding messages and secure communications that I have was using a CEOI, so in other words, not much experience at all. Based on other notes made in the notebook, I agree with you that this comes from training. However, I still wonder why pages were trimmed.