Network Security and Cryptography: Module 1 Flashcards

A set of vocabulary-style flashcards covering security goals, attacks, architecture, cryptography models, and modular arithmetic basics.

Confidentiality

Information security aspect that hides information from unauthorized access to protect it from being endangered.

Integrity

Security goal requiring that changes to information are performed only by authorized entities and through authorized mechanisms.

Availability

Requirement that information and services be accessible to authorized users whenever they are required.

Security attack

Any action that compromises the security of information belonging to an organization.

Security mechanism

A process or device designed to detect, prevent, or recover from a security attack.

Security service

A communication or processing service that enhances the security of systems and information transfers to counter attacks using security mechanisms.

Snooping

An attack threatening confidentiality involving unauthorized access to or interception of data.

Traffic analysis

An attack threatening confidentiality where information is obtained by monitoring online traffic.

Modification

An attack threatening integrity where an attacker intercepts and changes a message.

Masquerading

An attack threatening integrity, also known as spoofing, where an attacker impersonates another entity.

Replaying

An attack threatening integrity where an attacker captures a copy of a message and sends it again later.

Repudiation

An attack threatening integrity where a sender denies sending a message or a receiver denies receiving a message.

Denial of service (DoS)

An attack threatening availability that slows down or completely interrupts a system's services.

Cryptography

Originating from Greek for 'secret writing,' it is the science and art of transforming messages to make them secure and immune to attacks.

Steganography

Originating from Greek for 'covered writing,' it involves hiding data within text or images.

Plaintext

The original message before it is processed by an encryption algorithm.

Ciphertext

The message that is sent through a channel after encryption has been applied.

Kerckhoff’s Principle

The concept that the security of a cipher must rely solely on the secrecy of the key, assuming the adversary knows the algorithm.

Cryptanalysis

The science and art of breaking secret codes.

Ciphertext-Only Attack

A cryptanalysis attack where the attacker only has access to the ciphertext to be decoded.

Known-Plaintext Attack

A cryptanalysis attack where the attacker has a collection of plaintext-ciphertext pairs to help find the key.

Chosen-Plaintext Attack

A known-plaintext attack where the attacker can select specific plaintext to be encrypted and observe the resulting ciphertext.

Chosen-Ciphertext Attack

A cryptanalysis attack where the attacker selects specific ciphertext and studies the resulting decrypted plaintext.

Integer Division Formula

The relationship defined as $a = q \times n + r$, where $a$ is divided by $n$ to get quotient $q$ and remainder $r$.

Greatest Common Divisor (gcd)

The largest integer that can divide two positive integers simultaneously.

Relatively prime

A condition where the greatest common divisor of two integers, $\text{gcd}(a, b)$, is equal to $1$.

Extended Euclidean Algorithm

An algorithm used to calculate the $\text{gcd}(a, b)$ and find integers $s$ and $t$ such that $as + bt = \text{gcd}(a, b)$.

Modulus

The second input ($n$) in the modulo operation that defines the set of residues.

Residue

The output ($r$) of a modulo operation.

Congruence Operator

The operator ( \text{\equiv} ) used to show that two integers have the same remainder when divided by the same modulus.

Additive Inverse

Two numbers $a$ and $b$ in $Z_n$ such that (a + b) \text{\equiv} 0 \text{ (mod n)}.

Multiplicative Inverse

Two numbers $a$ and $b$ in $Z_n$ such that (a \times b) \text{\equiv} 1 \text{ (mod n)}.