Improved ciphertext-policy time using short elliptic curve Diffie–Hellman

Ciphertext-policy attribute-based encryption (CP-ABE) is a suitable solution for the protection of data privacy and security in cloud storage services. In a CP-ABE scheme which provides an access structure with a set of attributes, users can decrypt messages only if they receive a key with the desired attributes. As the number of attributes increases, the security measures are strengthened proportionately, and they can be applied to longer messages as well. The decryption of these ciphertexts also requires a large decryption key which may increase the decryption time. In this paper, we proposed a new method for improving the access time to the CP using a new elliptic curve that enables a short key size to be distributed to the users that allows them to use the defined attributes for encryption and decryption. Each user has a specially created key which uses the defined attributes for encryption and decryption based on the Diffie-Hellman method. After the implement, the results show that this system saves nearly half of the execution time for encryption and decryption compared to previous methods. This proposed system provides guaranteed security by means of the elliptic curve discrete logarithmic problem

Authentication and password storing improvement using SXR algorithm with a hash function

Secure password storing is essential in systems working based on password authentication. In this paper, SXR algorithm (Split, Exclusive OR, and Replace) was proposed to improve secure password storing and could also be applied to current authentication systems. SXR algorithm consisted of four steps. First, the received password from users was hashed through a general hash function. Second, the ratio and the number of iterations from the secret key (username and password) were calculated. Third, the hashed password and ratio were computed, and the hashed password was divided based on the ratio (Split) into two values. Both the values were applied to XOR equation according to the number of iterations, resulting in two new values. Last, the obtained values were concatenated and stored in the database (Replace). On evaluating, complexity analyses and comparisons has shown that SXR algorithm could provide attack resistance with a stronger hashed password against the aforementioned attacks. Consequently, even if the hackers hacked the hashed password, it would be challenging and would consume more time to decrypt the actual one, because the pattern of the stored password is the same as the one that has been hashed through the general hash function

Realistic propagation effects on wireless sensor networks for landslide management

Abstract This paper presents the development of propagation models for wireless sensor networks for landslide management systems. Measurements of path loss in potential areas of landslide occurrence in Thailand were set up. The effect of the vegetation and mountain terrain in the particular area was therefore taken into account regarding the measured path loss. The measurement was carried out with short-range transmission/reception at 2400 MHz corresponding to IEEE 802.15.4 wireless sensor networks. The measurement setup was divided into two main cases, namely, the transmitting and receiving antennas installed on the ground and 1-m high above the ground. The measurement results are shown in this paper and used to develop propagation models suitable for operation of short-range wireless sensor networks of landslide management systems. The propagation model developed for the first case was achieved by fitting the averaged experimental data by the log-normal model plus the standard deviation. For the second case, the model was derived from the ray tracing theory. The mountain-side reflection path was added into the model which contained the reflection coefficient defined for the soil property. Furthermore, the resulting propagation models were employed in order to realistically evaluate the performance of wireless sensor networks via simulations which were conducted by using Castalia. In the simulations, the sensor nodes were placed as deterministic and random distributions within square simulated networks. The comparison between the results obtained from the deterministic and random distributions are discussed