IT Support Course Flashcards
Bit
The smallest representation of data that a computer can understand
Border Gateway Protocol (BGP)
A protocol by which routers share data with each other
Broadcast
A type of Ethernet transmission, sent to every single device on a LAN
Broadcast address
A special destination used by an Ethernet broadcast composed by all Fs
Cable categories
Groups of cables that are made with the same material. Most network cables used today can be split into two categories, copper and fiber
Cables
Insulated wires that connect different devices to each other allowing data to be transmitted over them
Carrier-Sense Multiple Access with Collision Detection (CSMA/CD)
CSMA/CD is used to determine when the communications channels are clear and when the device is free to transmit data
Client
A device that receives data from a server
Collision domain
A network segment where only one device can communicate at a time
Computer networking
The full scope of how computers communicate with each other
Copper cable categories
These categories have different physical characteristics like the number of twists in the pair of copper wires. These are defined as names like category (or cat) 5, 5e, or 6, and how quickly data can be sent across them and how resistant they are to outside interference are all related to the way the twisted pairs inside are arranged
Crosstalk
Crosstalk is when an electrical pulse on one wire is accidentally detected on another wire
Cyclical Redundancy Check (CRC)
A mathematical transformation that uses polynomial division to create a number that represents a larger set of data. It is an important concept for data integrity and is used all over computing, not just network transmissions
Data packet
An all-encompassing term that represents any single set of binary data being sent across a network link
Datalink layer
The layer in which the first protocols are introduced. This layer is responsible for defining a common way of interpreting signals, so network devices can communicate
Destination MAC address
The hardware address of the intended recipient that immediately follows the start frame delimiter
Duplex communication
A form of communication where information can flow in both directions across a cable
Ethernet
The protocol most widely used to send data across individual links
Ethernet frame
A highly structured collection of information presented in a specific order
EtherType field
It follows the Source MAC Address in a dataframe. It’s 16 bits long and used to describe the protocol of the contents of the frame
Fiber Optic cable
Fiber optic cables contain individual optical fibers which are tiny tubes made of glass about the width of a human hair. Unlike copper, which uses electrical voltages, fiber cables use pulses of light to represent the ones and zeros of the underlying data
Five layer model
A model used to explain how network devices communicate. This model has five layers that stack on top of each other: Physical, Data Link, Network, Transport, and Application
Frame check sequence
It is a 4-byte or 32-bit number that represents a checksum value for the entire frame
Full duplex
The capacity of devices on either side of a networking link to communicate with each other at the exact same time
Half-duplex
It means that, while communication is possible in each direction, only one device can be communicating at a time
Hexadecimal
A way to represent numbers using a numerical base of 16
Hub
It is a physical layer device that broadcasts data to everything computer connected to it
Internet Protocol (IP)
The most common protocol used in the network layer
Internet Service Provider (ISP)
A company that provides a consumer an internet connection
Internetwork
A collection of networks connected together through routers - the most famous of these being the Internet
Line coding
Modulation used for computer networks
Local Area Network (LAN)
A single network in which multiple devices are connected
MAC(Media Access Control) address
A globally unique identifier attached to an individual network interface. It’s a 48-bit number normally represented by six groupings of two hexadecimal numbers
Modulation
A way of varying the voltage of a constant electrical charge moving across a standard copper network cable
Multicast frame
If the least significant bit in the first octet of a destination address is set to one, it means you’re dealing with a multicast frame. A multicast frame is similarly set to all devices on the local network signal, and it will be accepted or discarded by each device depending on criteria aside from their own hardware MAC address
Network layer
It’s the layer that allows different networks to communicate with each other through devices known as routers. It is responsible for getting data delivered across a collection of networks
Network port
The physical connector to be able to connect a device to the network. This may be attached directly to a device on a computer network, or could also be located on a wall or on a patch panel
Network switch
It is a level 2 or data link device that can connect to many devices so they can communicate. It can inspect the contents of the Ethernet protocol data being sent around the network, determine which system the data is intended for and then only send that data to that one system
Node
Any device connected to a network. On most networks, each node will typically act as a server or a client
Octet
Any number that can be represented by 8 bits
Organizationally Unique Identifier (OUI)
The first three octets of a MAC address
OSI model
A model used to define how network devices communicate. This model has seven layers that stack on top of each other: Physical, Data Link, Network, Transport, Session, Presentation, and Application
Patch panel
A device containing many physical network ports
Payload
The actual data being transported, which is everything that isn’t a header
Physical layer
It represents the physical devices that interconnect computers
Preamble
The first part of an Ethernet frame, it is 8 bytes or 64 bits long and can itself be split into two sections
Protocol
A defined set of standards that computers must follow in order to communicate properly is called a protocol
Router
A device that knows how to forward data between independent networks
Server
A device that provides data to another device that is requesting that data, also known as a client
Simplex communication
A form of data communication that only goes in one direction across a cable
Source MAC address
The hardware address of the device that sent the ethernet frame or data packet. In the data packet it follows the destination MAC address
Start Frame Delimiter (SFD)
The last byte in the preamble, that signals to a receiving device that the preamble is over and that the actual frame contents will now follow
Transmission Control Protocol (TCP)
The data transfer protocol most commonly used in the fourth layer. This protocol requires an established connection between the client and server
Transport layer
The network layer that sorts out which client and server programs are supposed to get the data
Twisted pair cable
The most common type of cabling used for connecting computing devices. It features pairs of copper wires that are twisted together
Unicast transmission
A unicast transmission is always meant for just one receiving address
User Datagram Protocol (UDP)
A transfer protocol that does not rely on connections. This protocol does not support the concept of an acknowledgement. With UDP, you just set a destination port and send the data packet
Virtual LAN (VLAN)
It is a technique that lets you have multiple logical LANs operating on the same physical equipment
VLAN header
A piece of data that indicates what the frame itself is. In a data packet it is followed by the EtherType
802.1X
It is the IEEE standard for encapsulating EAP or Extensible Authentication Protocol traffic over the 802 networks
802.1X with EAP-TLS
Offers arguably the best security available, assuming proper and secure handling of the PKI aspects of it
Access Control Entries
The individual access permissions per object that make up the ACL
Access Control List (ACL)
It is a way of defining permissions or authorizations for objects
Accounting
Keeping records of what resources and services your users access or what they did when they were using your systems
Activation threshold
Triggers a pre-configured action when it is reached and will typically block the identified attack traffic for a specific amount of time
Advanced Encryption Standard (AES)
The first and only public cipher that’s approved for use with top secret information by the United States National Security Agency
Adware
Software that displays advertisements and collects data
Analyzing logs
The practice of collecting logs from different network and sometimes client devices on your network, then performing an automated analysis on them
Antivirus software
It monitors and analyze things like new files being created or being modified on the system in order to watch for any behavior that matches a known malware signature
Application policies
Defines boundaries of what applications are permitted or not, but they also help educate folks on how to use software more securely
Asymmetric encryption
Systems where different keys are used to encrypt and decrypt
Attack
An actual attempt at causing harm to a system
Attack surface
It’s the sum of all the different attack vectors in a given system
Attack vector
Method or mechanism by which an attacker or malware gains access to a network or system
Auditing
It involves reviewing records to ensure that nothing is out of the ordinary
Authentication
A crucial application for cryptographic hash functions
Authentication server (AS)
It includes the user ID of the authenticating user
Authorization
It pertains to describing what the user account has access to or doesn’t have access to
Availability
Means that the information we have is readily accessible to those people that should have it
Backdoor
A way to get into a system if the other methods to get in a system aren’t allowed, it’s a secret entryway for attackers
Baiting
An attack that happens through actual physical contact, enticing a victim to do something
Bastion hosts or networks
A server used to provide access to a private network from an external network
Binary whitelisting software
It’s a list of known good and trusted software and only things that are on the list are permitted to run
Biometric authentication
Authentication that uses Biometric data
Bind
It is how clients authenticate to the server
Botnet
A collection of one or more Bots
Bots
Machines compromised by malware that are utilized to perform tasks centrally controlled by an attacker
Block ciphers
The cipher takes data in, places that into a bucket or block of data that’s a fixed size, then encodes that entire block as one unit
Brute force attacks
A common password attack which consists of just continuously trying different combinations of characters and letters until one gets access
CA (Certificate authority)
It’s the entity that’s responsible for storing, issuing, and signing certificates. It’s a crucial component of the PKI system
Caesar cipher
A substitution alphabet, where you replace characters in the alphabet with others usually by shifting or rotating the alphabet, a set of numbers or characters
CBC-MAC (Cipher block chaining message authentication codes)
A mechanism for building MACs using block ciphers
CCMP (counter mode CBC-MAC protocol)
A mode of operation for block ciphers that allows for authenticated encryption
Central repository
It is needed to securely store and index keys and a certificate management system of some sort makes managing access to storage certificates and issuance of certificates easier
Certificate-based authentication
It is the most secure option, but it requires more support and management overhead since every client must have a certificate
Certificate fingerprints
These are just hash digests of the whole certificate, and aren’t actually fields in the certificate itself, but are computed by clients when validating or inspecting certificates
Certificate Revocation List (CRL)
A means to distribute a list of certificates that are no longer valid
Certificate Signature Algorithm
This field indicates what public key algorithm is used for the public key and what hashing algorithm is used to sign the certificate
Certificate Signature Value
The digital signature data itself
CIA Triad
Confidentiality, integrity, and availability. Three key principles of a guiding model for designing information security policies
Client certificates
They operate very similarly to server certificates but are presented by clients and allow servers to authenticate and verify clients
CMACs (Cipher-based Message Authentication Codes)
The process is similar to HMAC, but instead of using a hashing function to produce a digest, a symmetric cipher with a shared keys used to encrypt the message and the resulting output is used as the MAC
Code signing certificates
It is used for signing executable programs and allows users of these signed applications to verify the signatures and ensure that the application was not tampered with
Confidentiality
Keeping things hidden
Correlation analysis
The process of taking log data from different systems, and matching events across the systems
Counter-based tokens
They use a secret seed value along with the secret counter value that’s incremented every time a one-time password is generated on the device
Cross-site scripting (XSS)
A type of injection attack where the attacker can insert malicious code and target the user of the service
Cryptanalysis
Looking for hidden messages or trying to decipher coded message
Cryptographic hashing
It is distinctly different from encryption because cryptographic hash functions should be one directional
Cryptography
The overarching discipline that covers the practice of coding and hiding messages from third parties
Cryptology
The study of cryptography
Cryptosystem
A collection of algorithms for key generation and encryption and decryption operations that comprise a cryptographic service
Data binding and sealing
It involves using the secret key to derive a unique key that’s then used for encryption of data
Data exfiltration
The unauthorized transfer of data from a computer. It’s also a very important concern when a security incident happens
Data handling policies
Should cover the details of how different data is classified
Data information tree
A structure where objects will have one parent and can have one or more children that belong to the parent object
Decryption
The reverse process from encryption; taking the garbled output and transforming it back into the readable plain text
Defense in depth
The concept of having multiple overlapping systems of defense to protect IT systems
Denial-of-Service (DoS) attack
An attack that tries to prevent access to a service for legitimate users by overwhelming the network or server
DES (Data Encryption Standard)
One of the earliest encryption standards
Deterministic
It means that the same input value should always return the same hash value
DH (Diffie-Hellman)
A popular key exchange algorithm, named for its co-inventors
Dictionary attack
A type of password attack that tries out words that are commonly used in passwords, like password, monkey, football
Distinguished name (DN)
A unique identifier for each entry in the directory
Distributed Denial-of-Service (DDoS) attack
A DoS attack using multiple systems
DNS Cache Poisoning Attack
It works by tricking a DNS server into accepting a fake DNS record that will point you to a compromised DNS server
DSA (Digital Signature Algorithm)
It is another example of an asymmetric encryption system, though its used for signing and verifying data
Dynamic ARP inspection (DAI)
A feature on enterprise switches that prevents certain types of attacks
EAP-TLS
One of the more common and secure EAP methods
ECDH & ECDSA
Elliptic curve variants of Diffie-Hellman and DSA, respectively
Eliptic curve cryptography (ECC)
A public key encryption system that uses the algebraic structure of elliptic curves over finite fields to generate secure keys
Encapsulating security payload
It’s a part of the IPsec suite of protocols, which encapsulates IP packets, providing confidentiality, integrity, and authentication of the packets
Encryption
The act of taking a message (plaintext), and applying an operation to it (cipher), so that you receive a garbled, unreadable message as the output (ciphertext)
Encryption algorithm
The underlying logic or process that’s used to convert the plaintext into ciphertext
End-entity (leaf certificate)
A certificate that has no authority as a CA
Entropy pool
A source of random data to help seed random number generators
Entry point
the act to determine the entry point to figure out how the attacker got in, or what vulnerability the malware exploited
Evil twin
The premise of an evil twin attack is for you to connect to a network that is identical to yours but that is controlled by an attacker. Once connected to it, they will be able to monitor your traffic
Exploit
Software that is used to take advantage of a security bug or vulnerability
Extensible authentication protocol (EAP over LAN, or EAPOL)
A standard authentication protocol
Fail to ban
A common open source flood guard protection tool
File-based encryption
Guarantees confidentiality and integrity of files protected by encryption
FIPS (Federal Information Processing Standard)
The DES that was adopted as a federal standard for encrypting and securing government data
Flood guards
Provide protection against DoS or Denial of Service Attacks
Forward secrecy
This is a property of a cryptographic system so that even in the event that the private key is compromised, the session keys are still safe
Four-Way Handshake
It is designed to allow an AP to confirm that the client has the correct pairwise master key in a WPA-PSK setup without disclosing the PMK
Frequency analysis
The practice of studying the frequency with which letters appear in ciphertext
Full disk encryption (FDE)
It is the practice of encrypting the entire drive in the system
GTK (Groupwise Transient Key)
A temporal key, which is actually used to encrypt data
Hacker
Someone who attempts to break into or exploit a system
Half-open attacks
A way to refer to SYN floods
Hash collisions
Two different inputs mapping to the same output
Hashing (Hash function)
A type of function or operation that takes in an arbitrary data input and maps it to an output of a fixed size, called a hash or a digest
High value data
usually includes account information, like usernames and passwords. Typically, any kind of user data is considered high value, especially if payment processing is involved
HMAC (Keyed-Hash Message Authentication Codes)
It uses a cryptographic hash function along with a secret key to generate a MAC
Host-based firewalls
Protects individual hosts from being compromised when they’re used in untrusted and potentially malicious environments
HTTPS
It is the secure version of HTTP, the Hypertext Transfer Protocol
Hubs
Devices that serve as a central location through which data travels through; a quick and dirty way of getting packets mirrored to your capture interface
Identification
The idea of describing an entity uniquely
Impact
The impact of an incident is also an important issue to consider
Implicit deny
A network security concept where anything not explicitly permitted or allowed should be denied
Injection attacks
A common security exploit that can occur in software development and runs rampant on the web, where an attacker injects malicious code
Integrity
Means keeping our data accurate and untampered with
Intermediary (subordinate) CA
It means that the entity that this certificate was issued to can now sign other certificates
Intrusion detection and intrusion protection systems (IDS/IPS)
Operates by monitoring network traffic and analyzing it
IPsec (Internet Protocol security)
A VPN protocol that was designed in conjunction with IPv6
IP source guard (IPSG)
It can be enabled on enterprise switches along with DHCP snooping
Issuer Name
This field contains information about the authority that signed the certificate
Kerberos
A network authentication protocol that uses tickets to allow entities to prove their identity over potentially insecure channels to provide mutual authentication
Kerckhoff’s principle
A principle that states that a cryptosystem, or a collection of algorithms for key generation and encryption and decryption operations that comprise a cryptographic service should remain secure, even if everything about the system is known except for the key
Key
A crucial component of a cipher, which introduces something unique into your cipher
Key escrow
Allows encryption key to be securely stored for later retrieval by an authorized party
Key length
It defines the maximum potential strength of the system
Key signing parties
Organized by people who are interested in establishing a web of trust, and participants perform the same verification and signing
Key size
It is the total number of bits or data that comprises the encryption key
Keylogger
A common type of spyware that’s used to record every keystroke you make
Lightweight Directory Access Protocol (LDAP)
An open industry-standard protocol for accessing and maintaining directory services
Logic bomb
A type of Malware that’s intentionally installed
Logs analysis systems
They are configured using user-defined rules to match interesting or atypical log entries
L2TP (Layer 2 Tunneling Protocol)
It is typically used to support VPNs
MACs (Message Authentication Codes)
A bit of information that allows authentication of a received message, ensuring that the message came from the alleged sender and not a third party masquerading as them
Malware
A type of malicious software that can be used to obtain your sensitive information or delete or modify files
MD5
A popular and widely used hash function designed in the early 1990s as a cryptographic hashing function
Meddler in the middle (formerly known as Man in the Middle)
An attack that places the attacker in the middle of two hosts that think they’re communicating directly with each other
MIC (Message Integrity Check)
It is essentially a hash digest of the message in question
Monitor mode
It allows to scan across channels to see all wireless traffic being sent by APs and clients
Multifactor authentication (MFA)
A system where users are authenticated by presenting multiple pieces of information or objects
Network hardening
Is the process of securing a network by reducing its potential vulnerabilities through configuration changes, and taking specific steps
Network separation (network segmentation)
A good security principle for an IT support specialists to implement. It permits more flexible management of the network, and provides some security benefits. This is the concept of using VLANs to create virtual networks for different device classes or types
Network software hardening
Includes things like firewalls, proxies, and VPNs
Network time protocol (NTP)
A network protocol used to synchronize the time between the authenticator token and the authentication server
NIST
National Institute of Standards and Technology
Normalization
It’s the process of taking log data in different formats and converting it into a standardized format that’s consistent with a defined log structure
OAuth
An open standard that allows users to grant third-party websites and applications access to their information without sharing account credentials
One-time password (OTP)
A short-lived token, typically a number that’s entered along with a username and password
One-time password (OTP) tokens
Another very common method for handling multifactor
OpenID
An open standard that allows participating sites known as Relying Parties to allow authentication of users utilizing a third party authentication service
Organizational units (OUs)
Folders that let us group related objects into units like people or groups to distinguish between individual user accounts and groups that accounts can belong to
Packet sniffing (packet capture)
the process of intercepting network packets in their entirety for analysis
Pairwise Transient Key (PTK)
It is generated using the PMK, AP nonce, Client nonce, AP MAC address, and Client MAC address
Password attacks
Utilize software like password crackers that try and guess your password
Password salt
Additional randomized data that’s added into the hashing function to generate the hash that’s unique to the password and salt combination
PBKDF2 (Password Based Key Derivation Function 2)
Password Based Key Derivation Function 2
PCI DSS
Payment Card Industry Data Security Standard
Penetration testing
The practice of attempting to break into a system or network to verify the systems in place
PGP (Pretty Good Privacy) encryption
An encryption application that allows authentication of data along with privacy from third parties relying upon asymmetric encryption to achieve this
Phishing attack
It usually occurs when a malicious email is sent to a victim disguised as something legitimate
Physical tokens
They take a few different forms, such as a USB device with a secret token on it, a standalone device which generates a token, or even a simple key used with a traditional lock
PIN authentication method
It uses PINs that are eight-digits long, but the last digit is a checksum that’s computed from the first seven digits
Ping flood
It sends tons of ping packets to a system. If a computer can’t keep up with this, then it’s prone to being overwhelmed and taken down
PKI system
A system that defines the creation, storage and distribution of digital certificates
Platform key
It’s the public key corresponding to the private key used to sign the boot files
Port mirroring
Allows the switch to take all packets from a specified port, port range, or the entire VLAN and mirror the packets to a specified switch port
Pre-shared key
It’s the Wi-Fi password you share with people when they come over and want to use your wireless network
Principle of least privilege
Helps to ensure that sensitive data is only accessed by people who are authorized to access it
Privacy policies
Oversees the access and use of sensitive data
Promiscuous mode
A type of computer networking operational mode in which all network data packets can be accessed and viewed by all network adapters operating in this mode
Proxy:
Can be useful to protect client devices and their traffic. They also provide secure remote access without using a VPN
Pseudo-random
Something that isn’t truly random
Public key authentication
A key pair is generated by the user who wants to authenticate
Public key signatures
Digital signature generated by composing the message and combining it with the private key
RA (Registration Authority)
It is responsible for verifying the identities of any entities requesting certificates to be signed and stored with the CA
Rainbow table attacks
To trade computational power for disk space by pre-computing the hashes and storing them in a table
Rainbow tables
A pre-computed table of all possible password values and their corresponding hashes
Random numbers
A very important concept in encryption because it avoids some kind of pattern that an adversary can discover through close observation and analysis of encrypted messages over time
Ransomware
A type of attack that holds your data or system hostage until you pay some sort of ransom
RC4 (Rivest Cipher 4)
Asymmetric stream cipher that gained widespread adoption because of its simplicity and speed
Recoverability
How complicated and time-consuming the recovery effort will be
Remote attestation
The idea of a system authenticating its software and hardware configuration to a remote system
Remote Authentication Dial-in User Service (RADIUS)
A protocol that provides AAA services for users on a network
Reverse proxy
A service that might appear to be a single server to external clients, but actually represents many servers living behind it
Risk
The possibility of suffering a loss in the event of an attack on the system
Risk mitigation
Understanding the risks your systems face, take measures to reduce those risks, and monitor them
Rogue Access Point (AP) Attack
An access point that is installed on the network without the network administrator’s knowledge
Rogue DHCP server attack
An attacker can hand out DHCP leases with whatever information they want by deploying a rogue DHCP server on your network, setting a gateway address or DNS server, that’s actually a machine within their control
Root certificate authority
They are self signed because they are the start of the chain of trust, so there’s no higher authority that can sign on their behalf
Rootkit:
A collection of software or tools that an admin would use
RSA
One of the first practical asymmetric cryptography systems to be developed, named for the initials of the three co-inventors: Ron Rivest, Adi Shamir and Leonard Adleman
Screen lock
A security feature that helps prevent unwanted access by creating an action you have to do to gain entry
Secure boot protocol
It uses public key cryptography to secure the encrypted elements of the boot process
Secure channel
It is provided by IPsec, which provides confidentiality, integrity, and authentication of data being passed
Secure element
It’s a tamper resistant chip often embedded in the microprocessor or integrated into the mainboard of a mobile device
Secure Shell (SSH)
A secure network protocol that uses encryption to allow access to a network service over unsecured networks
Security
It’s all about determining risks or exposure understanding the likelihood of attacks; and designing defenses around these risks to minimize the impact of an attack
Security information and event management systems (SIEMS)
Form of centralized logging for security administration purposes
Security keys
Small embedded cryptoprocessors, that have secure storage of asymmetric keys and additional slots to run embedded code
Security through obscurity
The principle that if no one knows what algorithm is being used or general security practices, then one is safe from attackers
Seed value
A secret value that is used to initialize a process that is generated by software using one or more values
Self-signed certificate
This certificate has been signed by the same entity that issued the certificate
Serial number
A unique identifier for their certificate assigned by the CA which allows the CA to manage and identify individual certificates
Session hijacking (cookie hijacking)
A common meddler in the middle attack
Session key
The shared symmetric encryption key using TLS sessions to encrypt data being sent back and forth
Severity
Includes factors like what and how many systems were compromised and how the breach affects business functions
SHA1
It is part of the secure hash algorithm suite of functions, designed by the NSA and published in 1995
Shannon’s maxim
It states that the system should remain secure, even if your adversary knows exactly what kind of encryption systems you’re employing, as long as your keys remain secure
Single Sign-on (SSO)
An authentication concept that allows users to authenticate once to be granted access to a lot of different services and applications
Social engineering
An attack method that relies heavily on interactions with humans instead of computers
Software signing certificate
Trust mechanism where a software vendor can cryptographically sign binaries they distribute using a private key
Spear phishing
Phishing that targets individual or group - the fake emails may contain some personal information like your name, or the names of friends or family
Spoofing
When a source is masquerading around as something else
Spyware
The type of malware that’s meant to spy on you
SQL Injection Attack
An attack that targets the entire website if the website is using a SQL database
SSL 3.0
The latest revision of SSL that was deprecated in 2015
SSL/TLS Client Certificate
Certificates that are bound to clients and are used to authenticate the client to the server, allowing access control to a SSL/TLS service
SSL/TLS Server Certificate
A certificate that a web server presents to a client as part of the initial secure setup of an SSL, TLS connection
StartTLS
It permits a client to communicate using LDAP v3 over TLS
Steganography
The practice of hiding information from observers, but not encoding it
Stream ciphers
It takes a stream of input and encrypts the stream one character or one digit at a time, outputting one encrypted character or digit at a time
Subject:
This field contains identifying information about the entity the certificate was issued to
Subject Public Key Info
These two subfields define the algorithm of the public key along with the public key itself
Substitution cipher
An encryption mechanism that replaces parts of your plaintext with ciphertext
Symmetric key algorithm
Encryption algorithms that use the same key to encrypt and decrypt messages
SYN flood
The server is bombarded with SYN packets
TACACS+
It is a device access AAA system that manages who has access to your network devices and what they do on them
Tailgating
Gaining access into a restricted area or building by following a real employee in
Tcpdump
It’s a super popular, lightweight command-line based utility that you can use to capture and analyze packets
Threat
The possibility of danger that could exploit a vulnerability
Threats & password policies
Protects Data & IP, Data Protection, Infrastructure Defense, Identity Management, and users
Ticket granting service (TGS)
It decrypts the Ticket Granting Ticket using the Ticket Granting Service secret key, which provides the Ticket Granting Service with the client Ticket Granting Service session key
Time-based token (TOTP)
A One-Time-Password that’s rotated periodically
TKIP (Temporal Key Integrity Protocol):
To address the shortcomings of WEP security
TLS 1.2
The current recommended revision of SSL
TLS 1.2 with AES GCM
A specific mode of operation for the AES block cipher that essentially turns it into a stream cipher
TLS Handshake
A mechanism to initially establish a channel for an application to communicate with a service
TPM (Trusted Platform Module)
This is a hardware device that’s typically integrated into the hardware of a computer, that’s a dedicated crypto processor
Transport mode
One of the two modes of operations supported by IPsec. When used, only the payload of the IP packet is encrypted, leaving the IP headers untouched
Trojan
malware that disguises itself as one thing but does something else
Trusted execution environment (TEE)
It provides a full-blown isolated execution environment that runs alongside the main OS
Tunnel
It is provided by L2TP, which permits the passing of unmodified packets from one network to another
Tunnel mode
One of the two modes of operations supported by IPsec. When used, the entire IP packet, header, payload, and all, is encrypted and encapsulated inside a new IP packet with new headers
Unbind
It closes the connection to the LDAP server
Username and password authentication
Can be used in conjunction with certificate authentication, providing additional layers of security
U2F (Universal 2nd Factor)
It’s a standard developed jointly by Google, Yubico and NXP Semiconductors that incorporates a challenge-response mechanism, along with public key cryptography to implement a more secure and more convenient second-factor authentication solution
Validity
This field contains two subfields, Not Before and Not After, which define the dates when the certificate is valid for
Vendor risk review
Questionnaire that covers different aspects of their security policies procedures and defenses
Version
What version of the X.509 standard certificate adheres to
Viruses
The best known type of malware
VPN (Virtual Private Network)
A secure method of connecting a device to a private network over the internet
VPNs
Commonly used to provide secure remote access, and link two networks securely
Vulnerability
A flaw in the system that could be exploited to compromise the system
Vulnerability scanner
Detect lots of things, ranging from misconfigured services that represent potential risks, to detecting the presence of back doors and systems
Web of trust
It is where individuals instead of certificate authorities sign other individuals’ public keys
WEP (Wired Equivalent Privacy)
First security protocol introduced for Wi-FI networks
Wireshark
It’s another packet capture and analysis tool that you can use, but it’s way more powerful when it comes to application and packet analysis, compared to tcpdump
Worms
They are similar to viruses except that instead of having to attach themselves onto something to spread, worms can live on their own and spread through channels like the network
WPA (Wi-fi protected access)
Designed as a short-term replacement that would be compatible with older WEP-enabled hardware with a simple firmware update
WPA2 Enterprise
It’s an 802.1x authentication to Wi-Fi networks
WPS (Wifi Protected Setup)
It’s a convenience feature designed to make it easier for clients to join a WPA-PSK protected network
X.509 standard
It is what defines the format of digital certificates, as well as a certificate revocation list or CRL
XTACACS
It stands for Extended TACACS, which was a Cisco proprietary extension on top of TACACS
0-Day Vulnerability (Zero Day)
A vulnerability that is not known to the software developer or vendor, but is known to an attacker
404 Not Found
An error message you might see on websites that have been moved or deleted
AAA (authentication, authorization, accounting)
The services that the directory services provide to all the computers within a company or organization
Abstraction
To take a relatively complex system and simplify it for our use
Absolute path
It is one that starts from the main directory
ACI
Access Control Lists
ACK flag
One of the TCP control flags. ACK is short for acknowledge. A value of one in this field means that the acknowledgment number field should be examined
Acknowledgement number
The number of the next expected segment in a TCP sequence
Active directory (AD)
The Microsoft alternative to directory services that offers customization and added features for the Windows platform
Active directory users and computers (ADUC)
The client tools that are used for accessing and administering a directory server
Address bus
Connects the CPU to the MCC and sends over the location of the data, but not the data itself
Address class system
A system which defines how the global IP address space is split up
Address Resolution Protocol (ARP)
A protocol used to discover the hardware address of a node with a certain IP address
Ad-Hoc network
A network configuration without supporting network infrastructure. Every device involved with the ad-hoc network communicates with every other device within range, and all nodes help pass along messages
Administrator
A user that has complete control over a machine
Advanced group policy management (AGPM)
A set of add-on tools from Microsoft that gives some added provision control abilities in GPMC
Algorithm
A series of steps that solves specific problems
Alias
A nickname for common commands
Android
A mobile operating system based on Linux
Anycast
A technique that’s used to route traffic to different destinations depending on factors like location, congestion, or link health
Appending flags
A way to add the data of the file without erasing existing data
Application
A computer program designed for a specific use
Application layer
The layer that allows network applications to communicate in a way they understand
Application layer payload
The entire contents of whatever data applications want to send to each other
Application software
Any software created to fulfill a specific need, like a text editor, web browser, or graphics editor
App store apps
A Package Manager that acts as a repository
App store repository
A app store service that also acts as a repository
App stores
A central managed marketplace for app developers to publish and sell mobile apps
APPX
An APPX is another way to package contents of a file to act like a unit of distribution
Archive
An archive is comprised of one or more files that are compressed into a single file” for verb agreement
A record:
The most common resource record, used to point a certain domain name at a certain IPv4 IP address
ARPANET
The earliest version of the Internet that we see today, created by the US government project DARPA in the 1960s
ARP table
A list of IP addresses and the MAC addresses associated with them
ASCII
The oldest character encoding standard used is ASCII. It represents the English alphabet, digits, and punctuation marks
ASN
Autonomous System Number is a number assigned to an individual autonomous system
Assembly language
A language that allowed computer scientists to use human readable instructions, assembled into code that the machines could understand
Asymmetric Digital Subscriber Line (ADSL)
A device that establishes data connections across phone lines and different speeds for uploading and downloading data
ATA
The most common interface that hard drives use to connect to our system
ATX (Advanced Technology eXtended)
The most common form factor for motherboards
Automatic allocation
A range of IP addresses is set aside for assignment purposes
Automation
It makes processes work automatically
Autoscaling
A system that allows the service to increase or reduce capacity as needed, while the service owner only pays for the cost of the machines that are in use at any given time
Background processes/Daemon processes
Processes that run or take place in the background
Backup and restore
A Microsoft offer and first party solution that has modes of operation, as a file based version where files are backed up to a zip archive
Backward compatible
It means older hardware works with newer hardware
Bash
The language used to interact with the shell
Baud rate
A measurement of how many bits could be passed across a phone line in a second
Binary system
The communication that a computer uses is referred to as binary system, also known as base-2 numeral system
Bind operation
The operation which authenticates clients to the directory server
Biometric data
A way of protecting your accounts and information using biometric data such as facial recognition and fingerprint
BIOS/UEFI
A low-level software that initializes our computer’s hardware to make sure everything is good to go
Bios (Basic Input Output Services)
The BIOS is software that helps initialize the hardware in our computer and gets our operating system up and running
Block ciphers
The cipher takes data in, places that into a bucket or block of data that’s a fixed size, then encodes that entire block as one unit
Block devices
A system that acts like USB drives and hard drive by transmitting data
Block storage
It improves faster handling of data because the data isn’t stored in one long piece but in blocks, so it can be accessed more quickly
Bluetooth
The most common short range wireless network
Boot
To start up a computer
Bootloader
A small program that loads the operating system
Botnet
A collection of one or more Bots
Bots
Machines compromised by malware that are utilized to perform tasks centrally controlled by an attacker
Broadband
Any connectivity technology that isn’t dial-up Internet
Browser
A user interface for displaying and interacting with web pages
BYOD (Bring Your Own Device)
Refers to the practice of allowing people to use their own personal devices for work
Byte
A group of 8 bits
Cable modem
A device that sits at the edge of a consumer’s network and connects it to the cable modem termination system
Cable modem termination system
Connects lots of different cable connections to an ISP’s core network
Cache
The assigned stored location for recently or frequently accessed data; on a mobile app it is where anything that was changed or created with that app is stored
Caching and recursive name servers
They are generally provided by an ISP or your local network, and their purpose is to store domain name lookups for a certain amount of time
Centralized logging
Parsing logs in one central location
Central management
A central service that provides instructions to all of the different parts of my IT infrastructure
Change management process
The process to notify others in the organization about the changes that you are about to make
Channels
Individual, smaller sections of the overall frequency band used by a wireless network
Character devices
A way to transmit data character by character like a keyboard and mouse
Character encoding
Is used to assign our binary values to characters so that we as humans can read them
Charge cycle
One full charge and discharge of a battery
Child directories
It is a directory housed by a parent directory
Children’s Online Privacy Protection Act (COPPA)
Regulates the information we show to children under the age of 13
Chipset
It decides how components talk to each other on our machine
