Definitions Flashcards
3DES
Triple Digital Encryption Standard. A symmetric algorithm used to encrypt data and provide confidentiality. It is a block cipher that encrypts data in 64-bit blocks.
AAA
Authentication, authorization, and accounting. A group of technologies used in remote access systems. Authentication verifies a user’s identification. Authorization determines if a user should have access. Accounting tracks a user’s access with logs. Sometimes called AAAs of security.
ABAC
Attribute-based access control. An access control model that grants access to resources based on attributes assigned to subjects and objects.
acceptable use policy (AUP)
A policy defining proper system usage and the rules of behavior for employees. It often describes the purpose of computer systems and networks, how users can access them, and the responsibilities of users when accessing the systems.
access point (AP)
A device that connects wireless clients to wireless networks. Sometimes called wireless access point (WAP).
accounting
The process of tracking the activity of users and recording this activity in logs. One method of accounting is audit logs that create an audit trail.
ACLs
Access control lists. Lists of rules used by routers and stateless firewalls. These devices use the ACL to control traffic based on networks, subnets, IP addresses, ports, and some protocols.
active reconnaissance
A penetration testing method used to collect information. It sends data to systems and analyzes responses to gain information on the target. Compare with passive reconnaissance.
ad hoc
A connection mode used by wireless devices without an AP. When wireless devices connect through an AP, they are using infrastructure mode.
administrative controls
Security controls implemented via administrative or management methods.
AES
Advanced Encryption Standard. A strong symmetric block cipher that encrypts data in 128-bit blocks. AES can use key sizes of 128 bits, 192 bits, or 256 bits.
affinity
A scheduling method used with load balancers. It uses the client’s IP address to ensure the client is redirected to the same server during a session.
aggregation switch
A switch used to connect multiple switches together into a network. Switches connect to the aggregation switch and it connects to a router.
agile
A software development life cycle model that focuses on interaction between customers, developers, and testers. Compare with waterfall.
AH
Authentication Header. An option within IPsec to provide authentication and integrity.
airgap
A physical security control that provides physical isolation. Systems separated by an airgap don’t typically have any physical connections to other systems.
ALE
Annual (or annualized) loss expectancy. The expected loss for a year. It is used to measure risk with ARO and SLE in a quantitative risk assessment. The calculation is SLE × ARO = ALE.
amplification attack
An attack that increases the amount of bandwidth sent to a victim.
anomaly
A type of monitoring on intrusion detection and intrusion prevention systems. It detects attacks by comparing operations against a baseline. It is also known as heuristic detection.
ANT
A proprietary wireless protocol used by some mobile devices. It is not an acronym.
antispoofing
A method used on some routers to protect against spoofing attacks. A common implementation is to implement specific rules to block certain traffic.
antivirus
Software that protects systems from malware. Although it is called antivirus software, it protects against most malware, including viruses, Trojans, worms, and more.
application blacklist
A list of applications that a system blocks. Users are unable to install or run any applications on the list.
application cell
Also known as application containers. A virtualization technology that runs services or applications within isolated application cells (or containers). Each container shares the kernel of the host.
application whitelist
A list of applications that a system allows. Users are only able to install or run applications on the list.
APT
Advanced persistent threat. A group that has both the capability and intent to launch sophisticated and targeted attacks.
ARO
Annual (or annualized) rate of occurrence. The number of times a loss is expected to occur in a year. It is used to measure risk with ALE and SLE in a quantitative risk assessment.
arp
A command-line tool used to show and manipulate the Address Resolution Protocol (ARP) cache.
ARP poisoning
An attack that misleads systems about the actual MAC address of a system.
asset value
An element of a risk assessment. It identifies the value of an asset and can include any product, system, resource, or process. The value can be a specific monetary value or a subjective value.
asymmetric encryption
A type of encryption using two keys to encrypt and decrypt data. It uses a public key and a private key. Compare with symmetric encryption.
attestation
A process that checks and validates system files during the boot process. TPMs sometimes use remote attestation, sending a report to a remote system for attestation.
audit trail
A record of events recorded in one or more logs. When security professionals have access to all the logs, they can re-create the events that occurred leading up to a security incident.
authentication
The process that occurs when a user proves an identity, such as with a password.
authorization
The process of granting access to resources for users who prove their identity (such as with a username and password), based on their proven identity.
availability
One of the three main goals of information security known as the CIA security triad. Availability ensures that systems and data are up and operational when needed. Compare with confidentiality and integrity.
backdoor
An alternate method of accessing a system. Malware often adds a
backdoor into a system after it infects it.
background check
A check into a person’s history, typically to determine eligibility for a job.
banner grabbing
A method used to gain information about a remote system. It identifies the operating system and other details on the remote system.
bcrypt
A key stretching algorithm. It is used to protect passwords. Bcrypt salts passwords with additional bits before encrypting them with Blowfish. This thwarts rainbow table attacks.
BIOS
Basic Input/Output System. A computer’s firmware used to manipulate different settings such as the date and time, boot drive, and access password. UEFI is the designated replacement for BIOS.
birthday
A password attack named after the birthday paradox in probability theory. The paradox states that for any random group of 23 people, there is a 50 percent chance that 2 of them have the same birthday.
black box test
A type of penetration test. Testers have zero knowledge of the environment prior to starting the test. Compare with gray box test and white box test.
block cipher
An encryption method that encrypts data in fixed-sized blocks. Compare with stream cipher.
Blowfish
A strong symmetric block cipher. It encrypts data in 64-bit blocks and supports key sizes between 32 and 448 bits. Compare with Twofish.
bluejacking
An attack against Bluetooth devices. It is the practice of sending unsolicited messages to nearby Bluetooth devices.
bluesnarfing
An attack against Bluetooth devices. Attackers gain unauthorized access to Bluetooth devices and can access all the data on the device.
bollards
Short vertical posts that act as a barricade. Bollards block vehicles but not people.
bots
Software robots that function automatically. A botnet is a group of computers that are joined together. Attackers often use malware to join computers to a botnet, and then use the botnet to launch attacks.
BPA
Business partners agreement. A written agreement that details the relationship between business partners, including their obligations toward the partnership.
bridge
A network device used to connect multiple networks together. It can be used instead of a router in some situations.
brute force
A password attack that attempts to guess a password. Online brute force attacks guess passwords of online systems. Offline attacks guess passwords contained in a file or database.
buffer overflow
An error that occurs when an application receives more input, or different input, than it expects. It exposes system memory that is normally inaccessible.
business impact analysis (BIA)
A process that helps an organization identify critical systems and components that are essential to the organization’s success.
BYOD
Bring your own device. A mobile device deployment model. Employees can connect their personally owned device to the network. Compare with COPE and CYOD.
CA
Certificate Authority. An organization that manages, issues, and signs certificates. A CA is a main element of a PKI.
CAC
Common Access Card. A specialized type of smart card used by the U.S. Department of Defense. It includes photo identification and provides confidentiality, integrity, authentication, and non-repudiation.
captive portal
A technical solution that forces wireless clients using web browsers to complete a process before accessing a network. It is often used to ensure users agree to an acceptable use policy or pay for access.
carrier unlocking
The process of unlocking a mobile phone from a specific cellular provider.
CBC
Cipher Block Chaining. A mode of operation used for encryption that effectively converts a block cipher into a stream cipher. It uses an IV for the first block and each subsequent block is combined with the previous block.
CCMP
Counter Mode with Cipher Block Chaining Message Authentication Code Protocol. An encryption protocol based on AES and used with WPA2 for wireless security. It is more secure than TKIP, which was used with the original release of WPA.
CER
Canonical Encoding Rules. A base format for PKI certificates. They are binary encoded files. Compare with DER.
certificate
A digital file used for encryption, authentication, digital signatures, and more. Public certificates include a public key used for asymmetric encryption.
certificate chaining
A process that combines all certificates within a trust model. It includes all the certificates in the trust chain from the root CA down to the certificate issued to the end user.
chain of custody
A process that provides assurances that evidence has been controlled and handled properly after collection. Forensic experts establish a chain of custody when they first collect evidence.
change management
The process used to prevent unauthorized changes. Unauthorized changes often result in unintended outages.
CHAP
Challenge Handshake Authentication Protocol. An authentication mechanism where a server challenges a client. Compare with MS-CHAPv2 and PAP.
chroot
A Linux command used to change the root directory. It is often used for sandboxing.
ciphertext
The result of encrypting plaintext. Ciphertext is not in an easily readable format until it is decrypted.
clean desk policy
A security policy requiring employees to keep their areas organized and free of papers. The goal is to reduce threats of security incidents by protecting sensitive data.
clickjacking
An attack that tricks users into clicking something other than what they think they’re clicking.
cloud access security broker (CASB)
A software tool or service that enforces cloud-based security requirements. It is placed between the organization’s resources and the cloud, monitors all network traffic, and can enforce security policies.
cloud deployment models
Cloud model types that identify who has access to cloud resources. Public clouds are for any organization. Private clouds are for a single organization. Community clouds are shared among community organizations. A hybrid cloud is a combination of two or more clouds.
code signing
The process of assigning a certificate to code. The certificate includes a digital signature and validates the code.
cold site
An alternate location for operations. A cold site will have power and connectivity needed for activation, but little else. Compare with hot site and warm site.
collision
A hash vulnerability that can be used to discover passwords. A hash collision occurs when two different passwords create the same hash.
compensating controls
Security controls that are alternative controls used when a primary security control is not feasible.
compiled code
Code that has been optimized by an application and converted into an executable file. Compare with runtime code.
confidential data
Data meant to be kept secret among a certain group of people. As an example, salary data is meant to be kept secret and not shared with everyone within a company.
confidentiality
One of the three main goals of information security known as the CIA security triad. Confidentiality ensures that unauthorized entities cannot access data. Encryption and access controls help protect against the loss of confidentiality. Compare with availability and integrity.
configuration compliance scanner
A type of vulnerability scanner that verifies systems are configured correctly. It will often use a file that identifies the proper configuration for systems.
confusion
A cryptography concept that indicates ciphertext is significantly different than plaintext.
containerization
A method used to isolate applications in mobile devices. It isolates and protects the application, including any data used by the application.
context-aware authentication
An authentication method using multiple elements to authenticate a user and a mobile device. It can include identity, geolocation, the device type, and more.
continuity of operations planning
The planning process that identifies an alternate location for operations after a critical outage. It can include a hot site, cold site, or warm site.
control diversity
The use of different security control types, such as technical controls, administrative controls, and physical controls. Compare with vendor diversity.
controller-based AP
An AP that is managed by a controller. Also called a thin AP. Compare with fat AP.
COPE
Corporate-owned, personally enabled. A mobile device deployment
model. The organization purchases and issues devices to employees. Compare with BYOD and CYOD.
corrective controls
Security controls that attempt to reverse the impact of a security incident.
CRL
Certificate revocation list. A list of certificates that a CA has revoked. Certificates are commonly revoked if they are compromised, or issued to an employee who has left the organization.
crossover error rate
Thepoint where the false acceptance rate (FAR) crosses over with the false rejection rate (FRR). A lower CER indicates a more accurate biometric system.
cross-site request forgery (XSRF)
A web application attack. XSRF attacks trick users into performing actions on web sites, such as making purchases, without their knowledge.
cross-site scripting (XSS)
A web application vulnerability. Attackers embed malicious HTML or JavaScript code into a web site’s code, which executes when a user visits the site.
crypto-malware
A type of ransomware that encrypts the user’s data.
crypto module
A set of hardware, software, and/or firmware that implements cryptographic functions. Compare with crypto service provider.
crypto service provider
A software library of cryptographic standards and algorithms. These libraries are typically distributed within crypto modules.
CSR
Certificate signing request. A method of requesting a certificate from a CA. It starts by creating an RSA-based private/public key pair and then including the public key in the CSR.
CTM
Counter mode. A mode of operation used for encryption that combines an IV with a counter. The combined result is used to encrypt blocks.
custom firmware
Mobile device firmware other than the firmware provided with the device. People sometimes use custom firmware to root Android devices.
cyber-incident response team
A group of experts who respond to security incidents. Also known as CIRT.
CYOD
Choose your own device. A mobile device deployment model. Employees can connect their personally owned device to the network as long as the device is on a preapproved list. Compare with BYOD and COPE.
DAC
Discretionary access control. An access control model where all objects have owners and owners can modify permissions for the objects (files and folders). Microsoft NTFS uses the DAC model.
data-at-rest
Any data stored on media. It’s common to encrypt sensitive data- at-rest.
data execution prevention (DEP)
A security feature that prevents code from executing in memory regions marked as nonexecutable. It helps block malware.
data exfiltration
The unauthorized transfer of data outside an organization.
data-in-transit
Any data sent over a network. It’s common to encrypt sensitive data-in-transit.
data-in-use
Any data currently being used by a computer. Because the computer needs to process the data, it is not encrypted while in use.
data retention policy
A security policy specifying how long data should be kept (retained).
data sovereignty
A term that refers to the legal implications of data stored in different countries. It is primarily a concern related to backups stored in alternate locations via the cloud.
DDoS
Distributed denial-of-service. An attack on a system launched from multiple sources intended to make a computer’s resources or services unavailable to users. DDoS attacks typically include sustained, abnormally high network traffic. Compare with DoS.
dead code
Code that is never executed or used. It is often caused by logic errors.
defense in depth
The use of multiple layers of security to protect resources. Control diversity and vendor diversity are two methods organizations implement to provide defense in depth.
degaussing
The process of removing data from magnetic media using a very powerful electronic magnet. Degaussing is sometimes used to remove data from backup tapes or to destroy hard disks.
DER
Distinguished Encoding Rules. A base format for PKI certificates. They are BASE64 ASCII encoded files. Compare with CER.
DES
Data Encryption Standard. A legacy symmetric encryption standard used to provide confidentiality. It has been compromised and AES or 3DES should be used instead.
detective controls
Security controls that attempt to detect security incidents after they have occurred.
deterrent controls
Security controls that attempt to discourage individuals from causing a security incident.
dictionary
A password attack that uses a file of words and character combinations. The attack tries every entry within the file when trying to guess a password.
differential backup
A type of backup that backs up all the data that has changed or is different since the last full backup.
Diffie-Hellman (DH)
An asymmetric algorithm used to privately share symmetric keys. DH Ephemeral (DHE) uses ephemeral keys, which are re- created for each session. Elliptic Curve DHE (ECDHE) uses elliptic curve cryptography to generate encryption keys.
diffusion
A cryptography concept that ensures that small changes in plaintext result in significant changes in ciphertext.
dig
A command-line tool used to test DNS on Linux systems. Compare with nslookup.
digital signature
An encrypted hash of a message, encrypted with the sender’s private key. It provides authentication, non-repudiation, and integrity.
disablement policy
A policy that identifies when administrators should
disable user accounts.
disassociation attack
An attack that removes wireless clients from a wireless network.
dissolvable agent
A NAC agent that runs on a client, but deletes itself later. It checks the client for health. Compare with permanent agent.
DLL injection
An attack that injects a Dynamic Link Library (DLL) into memory and runs it. Attackers rewrite the DLL, inserting malicious code.
DLP
Data loss prevention. A group of technologies used to prevent data loss. They can block the use of USB devices, monitor outgoing email to detect and block unauthorized data transfers, and monitor data stored in the cloud.
DMZ
Demilitarized zone. A buffer zone between the Internet and an internal network. Internet clients can access the services hosted on servers in the DMZ, but the DMZ provides a layer of protection for the internal network.
DNS
Domain Name System. A service used to resolve host names to IP addresses. DNS zones include records such as A records for IPv4 addresses and AAAA records for IPv6 addresses.
DNSSEC
Domain Name System Security Extensions. A suite of extensions to DNS used to protect the integrity of DNS records and prevent some DNS attacks.
DNS poisoning
An attack that modifies or corrupts DNS results. DNSSEC helps prevent DNS poisoning.
domain hijacking
An attack that changes the registration of a domain name without permission from the owner.
DoS
Denial-of-service. An attack from a single source that attempts to disrupt the services provided by the attacked system. Compare with DDoS.
downgrade attack
A type of attack that forces a system to downgrade its security. The attacker then exploits the lesser security control.
DSA
Digital signature algorithm. An encrypted hash of a message used for authentication, non- repudiation, and integrity. The sender’s private key encrypts the hash of the message.
dumpster diving
The practice of searching through trash looking to gain information from discarded documents. Shredding or burning papers helps prevent the success of dumpster diving.
EAP
Extensible Authentication Protocol. An authentication framework that provides general guidance for authentication methods. Variations include PEAP, EAP-TLS, EAP-TTLS, and EAP-FAST.
EAP-FAST
EAP-Flexible Authentication via Secure Tunneling (EAP- FAST). A Cisco-designed replacement for Lightweight EAP (LEAP). EAP- FAST supports certificates, but they are optional.
EAP-TLS
Extensible Authentication Protocol-Transport Layer Security. An
extension of EAP sometimes used with 802.1x. This is one of the most secure EAP standards and is widely implemented. It requires certificates on the 802.1x server and on the clients.
EAP-TTLS
Extensible Authentication Protocol-Tunneled Transport Layer Security. An extension of EAP sometimes used with 802.1x. It allows systems to use some older authentication methods such as PAP within a TLS tunnel. It requires a certificate on the 802.1x server but not on the clients.
ECB
Electronic Codebook. A legacy mode of operation used for encryption. It is weak and should not be used.
embedded system
Any device that has a dedicated function and uses a computer system to perform that function. It includes a CPU, an operating system, and one or more applications.
EMI
Electromagnetic interference. Interference caused by motors, power lines, and fluorescent lights. EMI shielding prevents outside interference sources from corrupting data and prevents data from emanating outside the cable.
EMP
Electromagnetic pulse. A short burst of energy that can potentially damage electronic equipment. It can result from electrostatic discharge (ESD), lightning, and military weapons.
encryption
A process that scrambles, or ciphers, data to make it unreadable. Encryption normally includes a public algorithm and a private key. Compare with asymmetric and symmetric encryption.
Enterprise
A wireless mode that uses an 802.1x server for security. It forces users to authenticate with a username and password. Compare with Open and PSK modes.
ephemeral key
A type of key used in cryptography. Ephemeral keys have very short lifetimes and are re-created for each session.
error handling
A programming process that handles errors gracefully.
ESP
Encapsulating Security Payload. An option within IPsec to provide
confidentiality, integrity, and authentication.
evil twin
A type of rogue AP. An evil twin has the same SSID as a legitimate AP.
exit interview
An interview conducted with departing employees just before they leave an organization.
exploitation frameworks
Tools used to store information about security vulnerabilities. They are often used by penetration testers (and attackers) to detect and exploit software.
extranet
The part of an internal network shared with outside entities. Extranets are often used to provide access to authorized business partners, customers, vendors, or others.
facial recognition
A biometric method that identifies people based on facial features.
false negative
A security incident that isn’t detected or reported. As an example, a NIDS false negative occurs if an attack is active on the network
but the NIDS does not raise an alert.
false positive
An alert on an event that isn’t a security incident. As an example, a NIDS false positive occurs if the NIDS raises an alert but activity on the network is normal.
FAR
False acceptance rate. Also called the false match rate. A rate that identifies the percentage of times a biometric authentication system incorrectly indicates a match.
Faraday cage
A room or enclosure that prevents signals from emanating beyond the room or enclosure.
fat AP
An AP that includes everything needed to connect wireless clients to a wireless network. Fat APs must be configured independently. Sometimes called a stand-alone AP. Compare with thin AP.
fault tolerance
The capability of a system to suffer a fault, but continue to operate. Said another way, the system can tolerate the fault as if it never occurred.
FDE
Full disk encryption. A method to encrypt an entire disk. Compare with SED.
federation
Two or more members of a federated identity management system. Used for single sign-on.
fingerprint scanners
Biometric systems that scan fingerprints for authentication.
firewall
A software or a network device used to filter traffic. Firewalls can be application-based (running on a host), or a network-based device. Stateful firewalls filter traffic using rules within an ACL. Stateless firewalls filter traffic based on its state within a session.
firmware OTA updates
Over-the-air updates for mobile device firmware that keep them up to date. These are typically downloaded to the device from the Internet and applied to update the device.
flood guard
A method of thwarting flood attacks. On switches, a flood guard thwarts MAC flood attacks. On routers, a flood guard prevents SYN flood attacks.
framework
A structure used to provide a foundation. Cybersecurity frameworks typically use a structure of basic concepts and provide guidance to professionals on how to implement security.
FRR
False rejection rate. Also called the false nonmatch rate. A rate that identifies the percentage of times a biometric authentication system incorrectly rejects a valid match.
FTPS
File Transfer Protocol Secure. An extension of FTP that uses TLS to encrypt FTP traffic. Some implementations of FTPS use TCP ports 989 and 990.
full backup
A type of backup that backs up all the selected data. A full backup could be considered a normal backup.
full tunnel
An encrypted connection used with VPNs. When a user is connected to a VPN, all traffic from the user is encrypted. Compare with split tunnel.
GCM
Galois/Counter Mode. A mode of operation used for encryption. It combines the Counter (CTM) mode with hashing techniques for data authenticity and confidentiality.
geofencing
A virtual fence or geographic boundary. It uses GPS to create the boundary. Apps can then respond when a mobile device is within the virtual fence.
geolocation
The location of a device identified by GPS. It can help locate a lost or stolen mobile device.
GPO
Group Policy Object. A technology used within Microsoft Windows to manage users and computers. It is implemented on a domain controller within a domain.
GPS
Global Positioning System. A satellite-based navigation system that identifies the location of a device or vehicle. Mobile devices often incorporate GPS capabilities.
GPS tagging
A process of adding geographical data to files such as pictures. It typically includes latitude and longitude coordinates of the location where the picture was taken or the file was created.
gray box test
A type of penetration test. Testers have some knowledge of the environment prior to starting the test. Compare with black box test and white box test.
group-based access control
A role-based access control method that uses groups as roles.
Guest account
A pre-created account in Windows systems. It is disabled by default.
hacktivist
An attacker who launches attacks as part of an activist movement or to further a cause.
hardware root of trust
A known secure starting point. TPMs have a private key burned into the hardware that provides a hardware root of trust.
hash
A number created by executing a hashing algorithm against data, such as a file or message. Hashing is commonly used for integrity. Common hashing algorithms are MD5, SHA-1, and HMAC.
heuristic/behavioral
A type of monitoring on intrusion detection and intrusion prevention systems. It detects attacks by comparing traffic against a baseline. It is also known as anomaly detection.
HIDS
Host-based intrusion detection system. Software installed on a system to detect attacks. It protects local resources on the host. A host-based intrusion prevention system (HIPS) is an extension of a HIDS. It is software installed on a system to detect and block attacks.
high availability
A term that indicates a system or component remains available close to 100 percent of the time.
HMAC
Hash-based Message Authentication Code. A hashing algorithm used to verify integrity and authenticity of a message with the use of a shared secret. It is typically combined with another hashing algorithm such as SHA.
hoax
A message, often circulated through email, that tells of impending doom from a virus or other security threat that simply doesn’t exist.
home automation
Smart devices used within the home that have IP addresses. These are typically accessible via the Internet and are part of the Internet of things (IoT).
honeypot
A server designed to attract an attacker. It typically has weakened security encouraging attackers to investigate it.
honeynet
A group of honeypots in a network. Honeynets are often configured in virtual networks.
hot and cold aisles
A method commonly used in data centers to keep equipment cool. Cool air flows from the front of the cabinets to the back, making the front aisle cooler and the back aisle warmer.
HOTP
HMAC-based One-Time Password. An open standard used for creating one-time passwords. It combines a secret key and a counter, and then uses HMAC to create a hash of the result.
hot site
An alternate location for operations. A hot site typically includes everything needed to be operational within 60 minutes. Compare with cold site and warm site.
HSM
Hardware security module. A removable or external device that can generate, store, and manage RSA keys used in asymmetric encryption. Compare with TPM.
HTTPS
Hypertext Transfer Protocol Secure. A protocol used to encrypt HTTP
traffic. HTTPS encrypts traffic with TLS using TCP port 443.
HVAC
Heating, ventilation, and air conditioning. A physical security control that increases availability by regulating airflow within data centers and server rooms.
IaaS
Infrastructure as a Service. A cloud computing model that allows an organization to rent access to hardware in a self-managed platform. Compare with PaaS and SaaS.
ICS
Industrial control system. A system that controls large systems such as power plants or water treatment facilities. A SCADA system controls the ICS.
identification
The process that occurs when a user claims an identity, such as with a username.
IEEE 802.1x
An authentication protocol used in VPNs and wired and wireless networks. VPNs often implement it as a RADIUS server. Wired networks use it for port-based authentication. Wireless networks use it in Enterprise mode. It can be used with certificate-based authentication.
