Selection, Molecular Identification and Testing of Potentially Probiotic Bacteria Recovered from Popular Artisanal Egyptian Cheeses

The present study was aimed to select potential probiotic and functional strains among lactic acid bacteria (LAB) isolated from some artisanal Egyptian dairy products. For this, 75 samples comprising karish (fresh skimmed), mish (aged salted skimmed) and Domiati (brined ripened) cheese varieties were surveyed in this study. Approximately, 300 lactic acid bacterial (LAB) strains were isolated and initially screened for their antibacterial activity against the two common food-borne pathogens; Staphylococcus aureus and Escherichia coli O157:H7. Using cell free extract of isolated LAB strains, various antimicrobial inhibition patterns have been noted against the tested pathogens. Upon further proteolytic and neutralization treatments, only 16 strains were proved to have potent antimicrobial attribute. Based on 16S rRNA gene sequencing identification of those 16 strains, 8 different species were identified (Lactobacillus plantarum, Lb. fermentum, Pediococcus acidilacticii and Enterococcus faecium). Additionally, those 16 strains were tested for different probiotic, functional and safety criteria (acid and bile resistance, salt tolerance, milk acidification ability, heamolytic activity and antibiotic sensitivity).  The present study showed that artisanal Egyptian artisanal chesses were proven to be sources of safe potentially probiotic LAB with interesting physiological properties, thus it could be further incorporated in manufacture of various dairy products as starter and non-starter cultures

On the cryptanalysis of a simplified AES using a hybrid binary grey wolf optimization

Cryptosystem cryptanalysis is regarded as an NP-Hard task in modern cryptography. Due to block ciphers that are part of a modern cipher and have nonlinearity and low autocorrelation in their structure, traditional techniques and brute-force attacks suffer from breaking the key presented in traditional techniques, and brute-force attacks against modern cipher S-AES (simplified-advanced encryption standard) are complex. Thus, developing robust and reliable optimization with high searching capability is essential. Motivated by this, this paper attempts to present a novel binary hybridization algorithm based on the mathematical procedures of the grey wolf optimizer (GWO) and particle swarm optimization (PSO), named BPSOGWO, to deal with the cryptanalysis of (S-AES). The proposed BPSOGWO employs a known plaintext attack that requires only one pair of plaintext– ciphertext pairs instead of other strategies that require more pairs (i.e., it reduces the number of messages needed in an attack, and secret information such as plaintext-ciphertext pairs cannot be obtained easily). The comprehensive and statistical results indicate that the BPSOGWO is more accurate and provides superior results compared to other peers, where it improved the cryptanalysis accurateness of S-AES by 82.5%, 84.79%, and 79.6% compared to PSO, GA, and ACO, respectively. Furthermore, the proposed BPSOGWO retrieves the optimal key with a significant reduction in search space compared to a brute-force attack. Experiments show that combining the suggested fitness function with HPSOGWO resulted in a 109-fold reduction in the search space. In cryptanalysis, this is a significant factor. The results prove that BPSOGWO is a promising and effective alternative to attack the key employed in the S-AES cipher.Web of Science1118art. no. 398

A Novel Binary Hybrid PSO-EO Algorithm for Cryptanalysis of Internal State of RC4 Cipher

Cryptography protects privacy and confidentiality. So, it is necessary to guarantee that the ciphers used are secure and cryptanalysis-resistant. In this paper, a new state recovery attack against the RC4 stream cipher is revealed. A plaintext attack is used in which the attacker has both the plaintext and the ciphertext, so they can calculate the keystream and reveal the cipher’s internal state. To increase the quality of answers to practical and recent real-world global optimization difficulties, researchers are increasingly combining two or more variations. PSO and EO are combined in a hybrid PSOEO in an uncertain environment. We may also convert this method to its binary form to cryptanalyze the internal state of the RC4 cipher. When solving the cryptanalysis issue with HBPSOEO, we discover that it is more accurate and quicker than utilizing both PSO and EO independently. Experiments reveal that our proposed fitness function, in combination with HBPSOEO, requires checking 104 possible internal states; however, brute force attacks require checking 2128 states