The term passive air defense is identified in base64 scheme by the sequence cGFzc2l2ZSBhaXIgZGVmZW5zZQ==, while the MD5 signature is equal to e7fad2657d2f831bda2c84e9fdd64dc1. The ASCII encoding of passive air defense in hexadecimal notation is 706173736976652061697220646566656e7365.