Chapter 12 Concealment Devices

Since the primary purpose for historical ninja was espionage, there was a need to transmit messages secretly across the countryside. Clever methods of concealing messages include the following1:

  • The bottom of the ninja sword's scabbard

  • Hollowed-out canes and walking sticks

  • Inside specially constructed arrows

  • Umbrellas

  • Food, such as walnut hulls and eggs with wax plugs

The ninja demonstrated extreme creativity in designing ways to conceal information in everyday items; the impetus for going to extreme lengths was the fact that they faced death if discovered. In traditional professional penetration testing, the risk of life or limb just does not exist – however, in cyber warfare between governments, the risks ...

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