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What is the Secure Hash Algorithm 1 (SHA-1)?
The Secure Hash Algorithm 1 (SHA-1) is a hash function that creates a message digest that can be used to prove if a message or file has been modified. It is not secure anymore as it was broken some years. Introduction The SHA-1 algorithm is based on the Merkle-Damgård construction. Find below an illustration of…
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What is the MD5 hash function (md5 message-digest)?
MD5 is a widely used hash function that produces a message digest (or hash value) of 128 bits in length. It was initially designed as a cryptographic hash function but, at a later stage vulnerabilities were found and therefore is not considered suitable for cryptographic applications. It was created in 1991 by Ronal Rivest and…
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What is the CIA Triad?
The CIA Triad is how computer security or cybersecurity experts refer to the concepts of Confidentiality, Integrity, and Availability altogether. These are major security goals in network security. Let’s see the definition of each concept and some examples. Definitions The main term related to the CIA Triad is Computer Security. Computer Security: Measures and controls…
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What is the OSI security architecture?
The Open System Interconnection (OSI) security architecture is a recommendation of the International Telecommunication Union which defines a systematic approach to define security requirements for a certain organization, as well as approaches to meet the aforementioned requirements. The OSI security architecture provides a general description of security services and mechanisms, as well as a description…
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What is the OSI model and how important is it in networking?
Data Networking is a way of electronically moving data from one location to another location. From a high-level view, it includes several protocols interconnected to move the information from one device to another one and it also includes hardware. The Open Systems Interconnection (OSI) Model is a reference model that provides standardization to Data Networking.…
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What is Galois/Counter Mode (GCM)?
The Galois/Counter Mode (GCM) is an algorithm for authenticated encryption that addresses confidentiality and authenticity at the same time. It is a NIST standard designed to avoid security flaws in authenticated encryption. GCM algorithm Find below a graphical representation of the GCM algorithm. This representation is based on the NIST recommendation. You can find the…
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What is Authenticated Encryption (AE)?
Authenticated Encryption (AE) is an encryption approach that addresses confidentiality and authenticity at the same time. Find below a summary of 4 approaches that aims to provide confidentiality and integrity at the same time. Approach Description Example of applications Encrypt, then authenticate – Generate two keys – Encrypt the message with the first key –…
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What is Elgamal Cryptographic System?
Elgamal is a public key scheme similar to the Diffie-Hellman (DH) cryptosystem. Find below the steps of Elgamal scheme. First, you have to generate your key-pair using the following steps: Choose a prime number q and a, such a is a primitive root of q Generate a random number XA, such that 1 < XA…
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Asymmetric Cryptography: The RSA algorithm (with examples)
The Rivest-Shamir-Adleman (RSA) algorithm is the most widely accepted approach in asymmetric cryptography. Asymmetric cryptography means that one key is used to encrypt and a different, but related one is used to decrypting the message. The RSA algorithm is as follows: Notice that from steps 1 to 6, you are just calculating the private and…
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Masquerade attack
What is a masquerade attack in network security? A masquerade is an attack where the attacker pretends to be someone else to gain unauthorized access to information or services. This attack is classified as an active attack. Also, it usually includes another type of active attack, like a man-in-the-middle attack, modification of messages, etc.…
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