Bacaris, Andrea B.; Dejacto, Ma. Genina S.  4  0   <br/><br/>
An enhanced key generation and key security of beaufort cipher expansion technique using pseudo-random number, key encryption, and alphabet extension applied in text data /        6 
       6     
Bacaris, Andrea B.; Dejacto, Ma. Genina S. 
 -   
 -     
 - 35 pp.     28 cm.     
 -   
 -   
 - 
 - 
 -         .
 -     .
 -          0   .
 -         .
 -  0       .
<br/><br/>   Undergraduate Thesis: (Bachelor of Science in Computer Science) Pamantasan ng Lungsod ng Maynila, 2023. 
<br/><br/>
<br/><br/>      
<br/><br/>   5 
<br/><br/>      
<br/><br/> ABSTRACT:  	This study aimed to improve the security of the Beaufort Cipher Expansion Technique by addressing the cipher's vulnerabilities to Kasiski attacks, brute force attacks, and frequency analysis attacks. The research objectives include modifying the key-generation process and the key-encryption process and improving the matrix to mitigate these vulnerabilities. The analysis of the Kasiski attack revealed that the enhanced Beaufort  Cipher Expansion Technique showed no pattern in the generated ciphertext, unlike the traditional Beaufort Cipher, which exhibited pattern. The result indicates that the enhanced technique effectively addressed the vulnerability to pattern recognition attacks. Also, the brute force attack analysis showed that it would 3.83376E+17 centuries to break a 10-letter ciphertext. The result indicates that the enhanced Beaufort cipher is strong against brute-force attacks. Regarding frequency analysis, the original Technique resulted in a ciphertext with frequent occurrences if specific values, making itsusceptible to such an attack. In contrast, the enhanced technique distributed characters evenly, making it more secure and challenging for attackers to extract meaningful information through frequency analysis. Furthermore, the avalanche effect analysis compared the enhanced technique with other relevant studies, and it achieved an avalanche effect of 51.66%, surpassing the desired value of 50%. The results indicate that determining which bits of the original message change when altering a random bit becomes challenging, thus further enhancing the cipher's security. Overall, the findings demonstrated that the enhanced Beaufort Cipher Expansion Technique effectively addressed the vulnerabilities to the Kasiski attack, brute force attack, and frequency analysis attack. The modifications improved the security of the cipher, making it a valuable contribution to the field of cryptography.       
<br/><br/>      
<br/><br/><br/> <br/> <br/> <br/> <br/> <br/> <br/> 
<br/><br/><br/>5     
<br/><br/><br/> <br/>   
<br/><br/><label>ISBN: </label>  
<br/><br/><label>ISSN: </label>2 
 =   
 =   
<br/><br/><label>Standard No.: </label>        
<br/><br/><label>Publisher. No.: </label>  
<br/><br/><label>Source: </label>        
<br/><br/><label>LCCN: </label>
<br/><br/><label>Nat. Bib. No.: </label> 2 
<br/><br/><label>Nat. Bib. Agency Control No.: </label>    
<br/><br/><label>Subjects--Personal Names: </label><br/>     2     --0------
<br/><br/><label>Subjects--Corporate Names: </label><br/>     6 --0-- 2 --------
<br/><br/><label>Subjects--Meeting Names: </label><br/><br/> 0    2 --
<br/><br/><label>Subjects--Uniform Titles: </label><br/>  --20------
<br/><br/><label>Subjects--Chronological Terms: </label><br/> 
<br/><br/><label>Subjects--Topical Terms: </label><br/>    --------20--
<br/><br/><label>Subjects--Geographic Terms: </label><br/>--------20--
<br/><br/><label>Index Terms--Genre/Form: </label><br/>----2
<br/><br/><label>LC Class. No.: </label> / 2 
<br/><br/><label>Dewey Class. No.: </label> / 2 
<br/><br/><label>National Agricultural Library Call No.: </label> /  
<br/><br/><label>National Library of Medicine Call No.: </label> /  
<br/><br/><label>Gov. Doc. Class. No.: </label>