China
Africa
Explore chapters and articles related to this topic
Attacks on Blockchain-Based Systems
Published in Rashmi Agrawal, Jyotir Moy Chatterjee, Abhishek Kumar, Pramod Singh Rathore, Blockchain Technology and the Internet of Things, 2020
Tejas Khajanchee, Deepak Kshirsagar
There is a specific phrase mentioned in the text above—“any kind of data”. Well what does that refer to? How will this algorithm apply to multimedia files (audio, video, image, etc.)? Such types of data are converted into text using something called base64 encoding or base32 encoding (Josefsson, 2003; 2006) and then supplied to SHA256. There is another important property that any strong cryptographic algorithm (Avalanche effect, n.d.) is expected to have—the avalanche effect. What this means is that there should be massive change in the output of a hash function even if there is a slightest change in the input (even a flip of a single bit). SHA256 does show this property. This is evident from the following example involving only a single bit flip. Let ‘#(x)’ represent application of SHA256 algorithm on input data ‘x’. Then, #(‘2’) =‘d4735e3a265e16eee03f59718b9b5d03019c07d8b6c51f90da3a666eec13ab35”#(‘3’) = ‘4e07408562bedb8b60ce05c1decfe3ad16b72230967de01f640b7e4729b49fce’
Implementation of AES Algorithm using Dynamic S-box on FPGA
Published in Rajesh Singh, Anita Gehlot, P.S. Ranjit, Dolly Sharma, Futuristic Sustainable Energy and Technology, 2022
Gadiparthi Mohan Chandu, Kommisetty Abhishek, Saimpu Lokesh, Varanasi Ramalingeswararao, Rajkumar Sarma
Avalanche effect is a beneficial property of any cryptographic algorithm which determines the security of data by calculating the change in number of bits in output by changing one bit in the input. Avalancheeffect=changeinnumberofbitsTotalnumberofbits
A genetic algorithm based image steganography scheme with high embedding capacity and low distortion
Published in The Imaging Science Journal, 2021
In the proposed method, the optimal chromosome obtained is treated as a secret key. The chromosome is 29 bit long therefore the secret key sample space contains or 536870912 different keys which is quite a large set. Considering this large set it becomes very difficult to try all possible keys so the brute force attack is almost impossible and the scheme may be considered as suitable for secure communication. Another measure in cryptography is to test the security of a certain scheme using the Avalanche effect, wherein if the secret key is changed by one bit, the corresponding change in output should be significant (e.g. half the output). We have tested the proposed method against the Avalanche effect by changing one bit at a time in the optimal chromosome. Further, the location pattern of optimal chromosomes and changed chromosomes are compared for similarity. Figure 5 depicts that in case of change in most bit positions, the percentage change is near to 50 % therefore it can be concluded that the proposed scheme follows the Avalanche effect and is robust against security attacks (Figure 6).