Table 7 Time required for Brute Force Attack.

From: DynBlock: dynamic data encryption with Toffoli gate for IoT

For 128-bit symmetric key

According to equation 6 : 2\(^{128\ }\)/ 2 \(\times\) 10\({ ^{9}}\) = 1.7 \(\times\) 10\(^{29}\)

Time in days = (1.7 \(\times\) 10\({^{29}}\))/ (60\(\times\)60\(\times\)24) = 1.96 \(\times\) 10\({ ^{24}}\)

Time in years = (1.96 \(\times\) 10\(^{24\ }\)) / 365 = 5.37 \(\times\) 10\(^{21}\) years (approx.)