When biometric authentication is performed on On-Body Wearable Wireless Networks, a cancelable template is useful to protect biometric information. A cancelable template generation method converts the original biometric information into irreversibly transformed information to protect the original biometric information. If a cancelable template is damaged or leaked, it can be replaced with another cancelable template. In 2017, Dwivedi et al. proposed a novel cancelable iris template generation scheme based on the randomized look-up table mapping. So far their scheme is the most accurate scheme with respect to EER compared to the previous cancelable iris template generation schemes. However, their scheme is not alignment-free and so is not efficient enough for wearable sensors. In the paper, we first suggest how to improve the accuracy of the Dwivedi et al.’s scheme using the partial sort technique. Our experiment result shows that our suggested scheme is more accurate than the Dwivedi et al.’s scheme under almost all parameter settings. More concretely, our scheme achieves EER 0.09%, whereas the Dwivedi et al.’s scheme achieves EER 0.43% in the best parameter settings for the CASIA-V3-Interval iris database. We also suggest how to improve the efficiency of the Dwivedi et al.’s scheme. Our second scheme is alignment-free by processing IrisCode column-wise, whereas the Dwivedi et al.’s scheme handles IrisCode row-wise. Our experiment shows that our second scheme is 15 times faster than the Dwivedi et al.’s scheme, so our scheme is efficient enough for wearable sensors. Though our second scheme has very high EER under some parameter settings, our second scheme achieves EER 0.53% in the best parameter settings for the CASIA-V3-Interval iris database.

Many applications are equipped to utilize drones to provide various services to users in Internet of Drones (IoD) environments. In such applications, it is necessary to make a session key between a drone and a user to establish an authenticated and secure channel. It is also desirable to provide strong anonymity to increase user(drone) privacy. To provide robust anonymity, a protocol has to provide both pseudonymity and unlinkability. If a protocol provides only pseudonymity without unlinkability, user(drone) privacy could be breached by analyzing communication frequency or user(drone) movement. On the other hand, we consider drone capture attacks in the IoD, because if a drone is captured, the secret information of the drone could be revealed. To minimize the damage against the capturing attacks, a key exchange should provide the forward unlinkability as well as forward secrecy. Forward unlinkability means that even though the secret information of the drone is revealed, the unlinkability is guaranteed. In the paper, we suggest the first key agreement protocols providing both pseudonymity and forward unlinkability, whereas previous key agreement protocols provide only pseudonymity and unlinkability.