Can cryptanalysis be used to communicate securely over an insecure communication channel?
Cryptanalysis, by its definition, is the study and practice of analyzing information systems in order to understand hidden aspects of the systems, typically with the intent of breaking cryptographic security systems and gaining access to the contents of encrypted messages, without being provided with the key normally required to do so. The term is fundamentally
- Published in Cybersecurity, EITC/IS/CCF Classical Cryptography Fundamentals, Introduction, Introduction to cryptography
Is mod K arithmetic used in a shift cipher, where K is the value of the key and denotes the number of shifted letters?
The question asks whether mod K arithmetic is used in a shift cipher, where K is the value of the key and denotes the number of shifted letters. To address this, a thorough analysis of the mechanics of shift ciphers, their mathematical underpinnings, and the precise use of modular arithmetic within their encryption and decryption
- Published in Cybersecurity, EITC/IS/CCF Classical Cryptography Fundamentals, History of cryptography, Modular arithmetic and historical ciphers
How many equivalence classes are there in modulo 3 arithmetic?
In the study of modular arithmetic, the concept of equivalence classes is central to understanding how numbers interact under modular operations. Specifically, when considering arithmetic modulo 3, the set of all integers is partitioned into a finite number of distinct equivalence classes, each corresponding to a unique possible remainder when dividing by 3. Definition and
- Published in Cybersecurity, EITC/IS/CCF Classical Cryptography Fundamentals, History of cryptography, Modular arithmetic and historical ciphers

