> One agent sees a chalk mark on the street and gets a real message at his dead drop, the other two see nothing and chill. One issue there would be that each t

> One agent sees a chalk mark on the street and gets a real message at his dead drop, the other two see nothing and chill. One issue there would be that each time they go out to parks or other places to check for dead drops they are risking getting exposed. I think by now most counter intel people expect OTP to be used so they are probably not spending an inordinate amount of resource on cracking them. As for broadcasting, maybe have OTP pads for groups and individuals. The first part of the message is encrypted with a group OTP which then either broadcasts a message to all members or indicates a particular member to use their individual pad to read the rest of the message. Even during transmission those can be compartmentalized so for example the head of the group can send a one to one message and encode it with that recipients OTP pad, but then hand the encrypted message to the radio person in charge of transmitting general the general group message.