Can the Diffie-Hellmann-protocol alone be used for encryption?
The Diffie-Hellman protocol, introduced by Whitfield Diffie and Martin Hellman in 1976, is one of the foundational protocols in the field of public-key cryptography. Its primary contribution is to provide a method for two parties to securely establish a shared secret key over an insecure communication channel. This capability is fundamental to secure communications, as
Was public-key cryptography introduced for use in encryption?
The question of whether public-key cryptography was introduced for the purpose of encryption requires an understanding of both the historical context and the foundational objectives of public-key cryptography, as well as the technical mechanisms underlying its most prominent early systems, such as RSA. Historically, cryptography was dominated by symmetric-key algorithms, where both parties shared a
- Published in Cybersecurity, EITC/IS/CCF Classical Cryptography Fundamentals, Introduction to public-key cryptography, The RSA cryptosystem and efficient exponentiation
Is the set of all possible keys of a particular cryptographic protocol referred to as the keyspace in cryptography?
Yes, in cryptography, the term "keyspace" specifically denotes the set of all possible keys that can be used within a particular cryptographic protocol or algorithm. This concept is foundational in understanding both the theoretical and practical aspects of cryptographic security. Keyspace size directly impacts the resistance of a cryptosystem to brute-force attacks and reflects the
- Published in Cybersecurity, EITC/IS/CCF Classical Cryptography Fundamentals, Introduction, Introduction to cryptography
Do the encryption and decryption functions need to be kept secret for the cryptographic protocol to remain secure?
The security model underlying modern cryptography is based on several well-established principles, the foremost of which is Kerckhoffs’s Principle. This tenet asserts that the security of a cryptographic protocol should rely solely on the secrecy of the key, not on the secrecy of the algorithms used for encryption or decryption. Hence, to address the question:
- Published in Cybersecurity, EITC/IS/CCF Classical Cryptography Fundamentals, Introduction, Introduction to cryptography
Do Internet, GSM, and wireless networks belong to the insecure communication channels?
Internet, GSM, and wireless networks are all considered insecure communication channels from the perspective of classical and modern cryptography. To understand why this is the case, one must examine the inherent properties of these channels, the types of threats they face, and the security assumptions made in cryptographic protocol design. 1. Definition of Secure vs.
- Published in Cybersecurity, EITC/IS/CCF Classical Cryptography Fundamentals, Introduction, Introduction to cryptography
What does the value K stand for in a shift cipher?
In classical cryptography, particularly in the context of the shift cipher—which is often referred to as the Caesar cipher—the value denoted by represents the key used for both encryption and decryption processes. The shift cipher is a type of substitution cipher where each letter in the plaintext is shifted by a fixed number of positions
- Published in Cybersecurity, EITC/IS/CCF Classical Cryptography Fundamentals, History of cryptography, Modular arithmetic and historical ciphers
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
Which bits of the key are used for parity checking in DES?
The Data Encryption Standard (DES) is a symmetric-key block cipher that was once a widely used method for data encryption. It operates on 64-bit blocks and uses a 56-bit key for encryption and decryption processes. One of the lesser-known aspects of DES is the inclusion of parity bits within its key structure, which are used
Does diffusion mean, that single bits of ciphertext are influenced by many bits of plaintext?
In the field of cryptography, particularly when discussing block ciphers and their modes of operation, the concept of diffusion plays a critical role in ensuring the security and robustness of encryption schemes. Diffusion is one of the two fundamental principles of secure cipher design, the other being confusion, as articulated by Claude Shannon, a pioneering
Is cryptography considered a part of cryptology and cryptanalysis?
Cryptography, cryptology, and cryptanalysis are interrelated fields within the domain of cybersecurity, each playing a important role in the protection and analysis of information. To understand their relationships and distinctions, it is essential to consider their definitions, purposes, and applications. Cryptography Cryptography is the science and art of creating codes and ciphers to protect information.