3-43. 3-44. 3-45. What are the primary advantages of (a) over-the-air rekey (OTAR) and  (b)  over-the-air transfer  (OTAT)? 1. 2. 3. 4. (a)  Requires  less circuit  downtime  for loading  keylists,  and (b)  no  operator  training required (a)  Reduces  distribution of  physical  keying material, and (b) eliminates  process  of loading  equipment  with key tapes (a)  Reduces  distribution of  physical  keying material,   and (b) no operator  training required (a)  Eliminates  process of  loading  equipment with key tapes, and (b) no  operator  training required What is the purpose of transmission   authentication? 1. 2. 3. 4. The To  guard  against fraudulent  or  simulated transmissions To inform the other operator that you are receiving  the transmission To  acknowledge  the transmission  of  the other  operator To allow the other operator  to  acknowledge your  transmission self-authentication method is used in which of the  following  transmissions? 1. Transmission  and  reply 2. Challenge  and  reply 3. Transmission authentication 4. Challenge   authentication 3-46. When you receive a message that has an authenticator in it,   what action, if any, are you required to take? 1. Prepare a message to challenge  the  originator 2. Send a message that you are in receipt of the message 3. Pass the message on to higher  authority  for them to challenge the originator 4. None 3-47. As an operator, you are required  to  authenticate  in which  of  the  following situations? 1. You  suspect  intrusion  on the circuit 2. You are requested to authenticate 3. You are requested to break  radio  silence 4. Each of the above A. Meaconing B. Interference C. Jamming D. Intrusion Figure 3D IN  ANSWERING  QUESTIONS  3-48  THROUGH 3-51, SELECT THE TERM FROM FIGURE 3D THAT IS DEFINED. 3-48. The  interception  and rebroadcast  of  navigational signals on the same frequency. 1.    A 2.   B 3.   C 4.   D 26