Account
A unique identifier that links a user, device, or process within a system, enabling access control, activity logging, and auditing.
Account Data
Data related to a specific account, including cardholder and authentication information, which must be protected under PCI standards. Account data consists of Cardholder Data and Sensitive Authentication Data.
Acquirer
A financial institution authorized to process card transactions on behalf of merchants, ensuring compliance with PCI DSS and payment brand rules.
Administrative Access
Elevated permissions granted to users or systems to manage settings, configurations, and security policies.
AES (Advanced Encryption Standard)
A robust encryption algorithm used for securing sensitive payment data via symmetric keys.
ANSI (American National Standards Institute)
U.S.-based organization that develops technical standards, including those used for cryptography and data security.
Anti-Malware
Security software designed to detect, prevent, and remove malicious software threats.
AOC (Attestation of Compliance)
Official document confirming status of a merchant’s or service provider’s PCI compliance.
APOs (Associate Participating Organizations)
Non-voting members of PCI SSC that contribute to development and review of security standards.
Application
Any software or digital platform within the PCI scope, including web, mobile, or desktop applications handling payment data.
Application and System Accounts
Service accounts with elevated privileges used to run processes, often without direct human interaction.
ASV (Approved Scanning Vendor)
A certified third-party provider authorized to conduct external vulnerability scans to identify risks, which met requirements as in ASV Program Guide.
Audit Log
A detailed, timestamped record of system activities used to support forensic investigations and compliance audits.
Authentication
The process of verifying an entity’s identity through credentials and security factors.
Authentication Credentials
The combination of an identifier, like a user ID, along with factors such as passwords or tokens used for verification.
Authentication Factor
One of the elements used to confirm identity, including knowledge, possession, or inherence.
Adaptive Authentication
Dynamic verification process that adjusts security requirements based on context, risk level, or behavior during login attempts.
Account Takeover (ATO)
A type of fraud where an attacker gains control of a legitimate account to perform unauthorized transactions.
Application Hardening
Techniques to secure applications against tampering, reverse engineering, or exploitation.
Authorization
The process of granting permission to perform actions after successful authentication, or clearing a payment transaction.
BAU (Business as Usual)
Ongoing security and compliance activities maintained during regular operations.
Bespoke and Custom Software
Unique software built to meet specific organizational needs, often subject to specialized PCI testing.
BoA (Board of Advisors)
Group providing strategic guidance to PCI SSC standards development.
Brute Force Attack
Automated guessing of passwords, keys, or cryptographic values until the correct one is found.
Buffer Overflow
Vulnerability where excess data overwrites adjacent memory, potentially allowing malicious code execution.
Behavioral Biometrics
Use of behavioral patterns, such as typing dynamics or mouse movements, for user verification and fraud prevention.
Biometric Authentication
The use of physical or behavioral traits—such as fingerprint, facial recognition, or voice—to verify identity.
Card Skimmer
Device secretly attached to card readers to capture card data illegally.
Card Verification Code
A temporary code printed on the card used to verify authenticity during remote transactions.
Cardholder
The individual who owns or is authorized to use a payment card.
Cardholder Data (CHD)
The full set of information—PAN, name, expiration date—that identifies the cardholder’s account.
CDE (Cardholder Data Environment)
The environment comprising systems that store, process, or transmit cardholder data and related sensitive information.
CERT (Computer Emergency Response Team)
Specialized unit that handles cybersecurity incidents and responds to breaches.
Change Control
Structured process for reviewing, testing, and approving system modifications with security impact analysis.
CIS (Center for Internet Security)
Organization publishing industry best practices and security benchmarks for PCI scope systems.
Cleartext Data
Unencrypted data in transit or storage, vulnerable if not protected.
Column-Level Database Encryption
Encryption applied only to specific database columns containing sensitive data.
Commercial Off-the-Shelf (COTS)
Pre-made hardware or software products available for commercial purchase without customization.
Compensating Controls
Alternative security measures used when a standard PCI requirement cannot be fully met but provides equivalent protection.
Crypt analysis
The study of analyzing cryptographic algorithms to identify vulnerabilities or weaknesses.
Cyber Kill Chain
Structured model describing how cyber attacks develop through various stages, useful for detection and prevention.
Cloud Access Security Broker (CASB)
Security policy enforcement point positioned between cloud service consumers and providers, ensuring compliance and data security in cloud environments.
Data-Flow Diagram
Visual representation showing how data moves through systems, highlighting points of vulnerability.
Default Account
Preconfigured account enabled during system setup, often with universal credentials.
Default Password
A factory-set password that is widely known and must be changed prior to use.
Defined Approach
A specified method for implementing PCI requirements, often documented for audit purposes.
Disk Encryption
Encryption method securing all stored data on a device or drive.
DMZ (Demilitarized Zone)
Network segment designed to host externally accessible systems securely.
DNS (Domain Name System)
System translating domain names into IP addresses.
DORA (Digital Operational Resilience Act)
EU regulation aimed at improving financial sector cybersecurity resilience.
Dual Control
Operational practice requiring two authorized persons to complete critical functions, such as cryptographic key management.
Data Masking
Concealing parts of sensitive data (like PAN) on screens or printouts to prevent unintentional disclosure.
Data Sovereignty
Legal requirement that data must be stored and processed within specific jurisdictions, impacting cloud and cross-border PCI compliance.
E-commerce Redirection Server
Server that redirects payment data securely to processing gateways.
ECC (Elliptic Curve Cryptography)
Cryptographic method combining efficiency and security, suitable for mobile or resource-constrained environments.
Encryption
The process transforming plain data into ciphertext utilizing cryptographic algorithms.
Encryption Algorithm
A mathematical process used to encrypt and decrypt data securely.
Entity
Organization undergoing PCI DSS validation or audit.
Endpoint Detection and Response (EDR)
Security solution that continuously monitors and responds to threats on endpoint devices.
Exploit Kit
Pre-packaged set of malicious tools designed to identify vulnerabilities and deploy malware.
Extended Detection and Response (XDR)
Integrated security approach combining multiple detection systems for broader threat visibility.
File Integrity Monitoring (FIM)
A security technology that detects and alerts on unauthorized changes, additions, or deletions to critical system files, aiding in the prevention and investigation of security incidents.
File-Level Encryption
Encryption applied to specific files rather than entire disks, protecting sensitive data contained within those files.
Firewall
Hardware or software that controls network traffic based on a set of security rules, protecting systems from unauthorized access and attacks.
Forensics
The application of investigative methods to collect and analyze digital evidence related to security breaches or data compromises.
FTP (File Transfer Protocol)
An older protocol for transferring files over a network, often insecure unless paired with encryption layers like SSH.
Fraud Analytics
Use of data analysis tools to detect and prevent fraudulent activities by identifying suspicious transaction patterns in payment environments.
GEAR (Global Executive Assessor Roundtable)
A PCI SSC forum addressing executive-level strategies and compliance challenges worldwide.
Gateway Tokenization
Process where a payment gateway replaces sensitive card data with tokens for safer transaction processing.
Geofencing Security
Security controls that restrict or trigger alerts based on user or device location with respect to predefined geographical boundaries.
Hashing
A one-way cryptographic function converting data into a fixed-length string, commonly used to verify data integrity without revealing the original data.
HSM (Hardware Security Module)
Secure physical device used to generate, store, and manage cryptographic keys while protecting against tampering and unauthorized access.
Honeypot
A deliberately vulnerable system designed to attract attackers, providing insight into threat methods and supporting defensive measures.
IDS (Intrusion Detection System)
A system that monitors network or system activities for malicious actions or policy violations and alerts administrators when detected.
Index Token
A unique, randomly generated value mapped to a specific PAN, used to anonymize cardholder data in secure systems.
Interactive Login
Authentication method where a user provides credentials directly to an application or system in real time.
IPS (Intrusion Prevention System)
An active security system that detects and takes automatic action to block malicious activities before they affect the system.
ISA (Internal Security Assessor)
An individual trained and qualified to assess their organization’s PCI DSS compliance internally.
ISO (International Organization for Standardization)
Global entity developing and publishing international technical standards, including those influencing payment security practices.
Issuer
Financial institution issuing payment cards to consumers, responsible for authorizing transactions and managing cardholder accounts.
Issuing Services
Services provided by issuers such as card personalization, authorization, and account management.
Incident Response Plan (IRP)
A documented strategy outlining roles, responsibilities, and procedures for managing and recovering from security incidents.
Insider Threat
Risk posed by individuals within an organization who have access to systems and data and who may intentionally or unintentionally compromise security.
Jurisprudence
The body of law, legal principles, and court decisions that influence the interpretation and enforcement of payment security and PCI compliance regulations.
JSON Web Token (JWT)
A compact, URL-safe means of representing claims to be transferred between two parties, often used in authentication and authorization systems to securely transmit user information.
Key Custodian
An individual or role entrusted with managing cryptographic keys securely, responsible for their generation, distribution, storage, and destruction in accordance with best practices.
Key Management System (KMS)
A hardware or software system that handles the lifecycle of cryptographic keys, ensuring secure generation, storage, rotation, and access control.
Keyed Cryptographic Hash
A hashing function combined with a secret key to verify data integrity and authenticity, resistant to forgery and brute force attacks.
Kerberos
A network authentication protocol that uses secret-key cryptography for secure user verification in trusted domains, diminishing the risk of credentials exposure.
LAN (Local Area Network)
A network confined to a limited geographical area such as a building or campus, used to connect systems and devices for internal communications secured under PCI requirements.
LDAP (Lightweight Directory Access Protocol)
A protocol facilitating the retrieval and organization of directory information, commonly used for centralized user authentication and authorization in PCI environments.
Least Privilege
A security principle advocating the granting of the minimal level of access or permissions necessary for users or processes to perform their roles, minimizing potential misuse or compromise.
MAC (Message Authentication Code)
A cryptographic checksum used to verify the integrity and authenticity of a message or data, ensuring it has not been altered in transit.
Magnetic-Stripe Data
Data stored on the magnetic stripe of a payment card, including cardholder account details used during traditional swipe transactions.
Masking
The partial obscuration of sensitive data elements, such as displaying only the last four digits of a PAN, to protect cardholder information while maintaining usability.
Media
Physical or digital storage entities containing sensitive cardholder data or authentication information, subject to strict PCI protection requirements.
Multi-Factor Authentication (MFA)
An authentication method that requires two or more verification factors from independent categories (knowledge, possession, inherence) to confirm identity, significantly enhancing access security.
NAC (Network Access Control)
A security solution ensuring that only authorized and compliant devices can access network resources, playing a crucial role in reducing PCI scope and risks.
NAT (Network Address Translation)
A method used in networking to remap IP addresses, often employed to hide internal network structures and enhance security in PCI environments.
Network Connection
Any physical or logical communication link between devices or systems allowing data exchange, requiring monitoring and control under PCI DSS.
Network Diagram
A detailed visual representation of network components and their interconnections critical for scoping and vulnerability assessments in PCI audits.
Network Security Controls (NSC)
Technologies and policies such as firewalls, intrusion detection/prevention systems, and segmentation that protect the network perimeter and internal segments from unauthorized access.
NIST (National Institute of Standards and Technology)
A U.S. federal agency that develops cybersecurity standards and guidelines widely referenced in PCI compliance frameworks and best practices.
Non-Console Access
Access to system components performed remotely or over a network rather than through direct physical console connection, necessitating robust authentication controls.
NTP (Network Time Protocol)
Protocol used to synchronize the clocks of network devices, essential for accurate logging and audit trails in PCI environments.
Organizational Independence
The structural separation within a company such that assessment personnel have no conflict of interest with management of the PCI environment, ensuring impartial compliance evaluations.
OWASP (Open Worldwide Application Security Project)
An open community and resource center providing guidelines, tools, and awareness for web application security, frequently referenced in PCI DSS web-related controls.
P2PE (Point-to-Point Encryption)
A security technology encrypting cardholder data from the point of interaction directly to a secure endpoint, minimizing exposure of sensitive data within a merchant’s environment.
PAN (Primary Account Number)
The unique numeric identifier printed on payment cards, constituting the core element of cardholder data protected under PCI DSS.
Participating Payment Brand
Payment card brands acknowledged as members of the PCI Security Standards Council with their unique compliance and operational rules.
Password / Passphrase
A secret string of characters used as an authentication factor to verify user identity or system access rights.
Patch
A software update intended to fix security vulnerabilities, bugs, or performance issues, critical for maintaining PCI DSS compliance through vulnerability management.
Payment Brand
An organization that issues branded payment cards or controls payment networks, enforcing compliance with security standards for their products.
Payment Card Form Factor
Physical or virtual manifestations of payment cards or devices that emulate card functions for transactions, including smartphones and wearables.
Payment Cards
Payment instruments, physical or virtual, adhering to brand standards and requiring protection under PCI DSS.
Payment Channel
The method of accepting payment transactions, such as card-present (in-person) or card-not-present (online or telephonic).
Payment Page
A web interface designed to securely capture payment data from consumers for processing transactions.
Payment Page Scripts
Client-side scripts executed on payment pages that must be controlled to prevent interception or manipulation of sensitive data.
Payment Processor
Entity facilitating payment transaction processing on behalf of merchants and acquirers, subject to PCI DSS controls.
PCI DSS (Payment Card Industry Data Security Standard)
A globally recognized set of security requirements designed to protect payment card data across all organizations handling such data.
Personnel
Employees, contractors, and third parties with responsibilities or access that could impact the security of payment card data.
Phishing Resistant Authentication
Authentication mechanisms designed to prevent credential theft through phishing attacks, often employing cryptographic hardware or asymmetric keys.
Physical Access Control
Security measures limiting physical entry to sensitive areas where PCI-relevant systems or data reside.
PIN (Personal Identification Number)
A numeric secret used as an authentication factor for cardholder identity verification during transactions.
PIN Block
An encrypted data construct encapsulating a PIN during transmission or storage, protecting it against disclosure.
POI (Point of Interaction)
The device or terminal where card data is initially captured from the cardholder during a transaction.
Point of Sale System (POS)
The hardware and software environment used by merchants to conduct payment acceptance activities.
Privileged User
A user with elevated access rights that exceeds normal user privileges, requiring stringent oversight.
QIR (Qualified Integrator or Reseller)
Specialists authorized by PCI to securely install and configure payment solutions, ensuring PCI compliance.
QPA (Qualified PIN Assessor)
Certified entity responsible for validating PIN security implementation.
QSA (Qualified Security Assessor)
An organization approved by PCI SSC to validate compliance with PCI DSS requirements.
REB (Regional Engagement Board)
A body facilitating regional collaboration and guidance on PCI implementations.
Remote Access
Access to systems or networks from an external location, requiring strong authentication and encryption controls to protect PCI scope.
Removable Electronic Media
Transportable storage media such as USB drives or CDs containing cardholder data subject to strict security policies.
RFC (Request for Comment)
Formal documents from standards organizations that influence PCI-related technologies or procedures.
Risk Assessment
The systematic process of identifying and evaluating risks to cardholder data, informing security strategy and controls.
Risk Ranking
The practice of prioritizing identified risks based on their severity and potential impact on the business.
ROC (Report on Compliance)
A detailed report documenting an entity’s PCI DSS assessment results.
SAQ (Self-Assessment Questionnaire)
A tool used by merchants and service providers to self-evaluate their PCI DSS compliance status.
Scoping
The process of defining the boundaries of the PCI environment, including system components and data flows.
Secure Coding
Development practices aimed at eliminating vulnerabilities within application code.
Security Event
Any occurrence that might have security implications or indicate a breach.
Security Officer
The person designated to oversee PCI-related security efforts within an organization.
Segmentation
Dividing a network to isolate PCI-relevant systems from other parts, reducing risk and scope.
Sensitive Area
Restricted locations where PCI data or related systems are stored or processed, requiring controlled access.
Sensitive Authentication Data (SAD)
Highly confidential information like full track data and PINs used during transaction authorization that must not be stored post-authorization.
Separation of Duties
Dividing responsibilities among personnel to reduce fraud and error risks.
Service Code
Code embedded in card track data indicating usage restrictions or service attributes.
Service Provider
Third-party entity involved in handling or impacting security of cardholder data on behalf of merchants or other service providers.
SNMP (Simple Network Management Protocol)
Protocol for managing devices on IP networks, which must be secured in PCI environments to prevent unauthorized access.
Split Knowledge
A security principle where critical cryptographic material is divided and separately held by different individuals.
SQL (Structured Query Language)
Programming language used to manage and query relational databases, often targeted in injection attacks if not properly secured.
SSH (Secure Shell)
A network protocol providing encrypted communication and secure remote login capabilities.
SSL (Secure Sockets Layer)
Legacy protocol for securing internet communications, replaced largely by TLS.
Strong Cryptography
Encryption and cryptographic techniques recognized as secure by current industry and government standards.
System Components
Any hardware or software that stores, processes, or transmits cardholder data or could impact its security.
TAB (Technical Advisory Board)
Expert group advising PCI SSC on technical matters regarding standards and security requirements.
Targeted Risk Analysis
Focused risk assessment addressing specific PCI requirements or controls to guide customized implementations.
TDES (Triple Data Encryption Standard)
A cryptographic standard applying DES encryption three times for enhanced data protection.
TELNET
A network protocol for remote command-line interface access, generally considered insecure without additional encryption layers.
TGG (Technology Guidance Group)
A PCI SSC committee that develops guidance materials and clarifications for implementation.
Third-Party Service Provider (TPSP)
An external organization providing services that involve payment data processing or influence on PCI security.
Third-Party Software
Software acquired from external sources that must be evaluated and secured within PCI environments.
TLS (Transport Layer Security)
Modern cryptographic protocol providing secure communication over networks, standard in PCI DSS for encrypting data in transit.
Token
A substitute value replacing sensitive data in transactions, reducing risk exposure of actual card data.
Track Data
Data encoded on a card’s magnetic stripe or chip containing cardholder information used during transactions.
Truncation
Removing parts of the PAN to make it unreadable beyond what is necessary for business needs, complementing masking.
Trusted Network
A network environment under strict control that meets PCI DSS requirements for protection of cardholder data.
Untrusted Network
Any network that does not meet trust or security criteria necessary for PCI DSS compliance.
Virtual Payment Terminal
Web-browser-based interface allowing merchants to manually enter payment details to process transactions.
Virtualization
Technology enabling multiple virtual machines or applications to run on shared physical resources, requiring careful security controls within PCI scope.
Visitor
Individual who has limited or no access to sensitive PCI areas, such as guests or external vendors without data access.
VPN (Virtual Private Network)
An encrypted tunnel over public or untrusted networks that secures remote network access to PCI environments.
Vulnerability
A flaw or weakness in a system that could be exploited to compromise security.
Web Application
Software accessible over the web that can process payment data, requiring specific PCI compliance measures to prevent attacks like SQL injection or XSS.