What Is PCI DSS?

5 min. read

The Payment Card Industry Data Security Standard (PCI DSS) is an information security standard, designed to reduce payment card fraud by obligating organizations that process or store credit card information to secure their environments. To adhere to the PCI DSS, these organizations need to implement security controls related to personal financial data.

The PCI DSS details requirements for protecting cardholder data, such as:

  • Encrypting data transmitted over networks
  • Regularly testing and maintaining security systems
  • Implementing strict access controls to cardholder data

In addition to technical measures, the PCI DSS also includes requirements for training and awareness programs for employees, as well as security policies and procedures to ensure that all employees understand their roles and responsibilities in maintaining a secure environment. Companies that fail to comply with the PCI DSS risk fines, loss of merchant accounts, and damage to their reputation.

PCI DSS Explained

The PCI DSS is designed to ensure that organizations processing, storing, or transmitting credit card information maintain a secure environment. Its requirements cover building and maintaining a secure network, protecting cardholder data, maintaining a vulnerability management program, implementing strong access control measures, regularly monitoring and testing networks, and maintaining an information security policy.

By implementing these requirements, organizations safeguard sensitive cardholder data and reduce the risk of data breaches or fraud.

PCI DSS is mandatory for all organizations that process, store, or transmit credit card information. Compliance with PCI DSS is required by major credit card brands, such as Visa, MasterCard, American Express, Discover, and JCB. Failure to comply with PCI DSS can lead to penalties, fines, increased transaction fees, or even the loss of the ability to process credit card transactions. The main objective of PCI DSS is to protect cardholder data and reduce the risk of data breaches or fraud in the payment card industry.

Why PCI DSS Compliance Is Important

PCI DSS compliance ensures that organizations dealing with credit card information maintain a secure environment, protect cardholder data, and minimize the risk of data breaches or fraud.

Data Security

Achieving PCI DSS compliance demonstrates that organizations have implemented security controls like encryption, secure storage, and secure data transmission to safeguard cardholder data.

Risk Mitigation

PCI DSS compliance ensures that organizations have established a proactive approach to identifying and addressing potential vulnerabilities and risks. This involves maintaining a vulnerability management program, regularly monitoring and testing networks, and implementing strong access control measures, which collectively help to prevent security incidents and data breaches.

Regulatory Compliance

Compliance with PCI DSS is a requirement imposed by major credit card brands, such as Visa, MasterCard, American Express, Discover, and JCB. Failing to comply with PCI DSS can result in penalties, fines, increased transaction fees, or even the loss of the ability to process credit card transactions. Thus, maintaining PCI DSS compliance is essential for organizations to meet their regulatory obligations and avoid potential financial and reputational consequences.

Customer Trust

In today's digital economy, consumers expect organizations to protect their sensitive information, including credit card data. PCI DSS compliance is an indicator that the organization takes its responsibility to protect cardholder data seriously, building customer trust and confidence in the organization's ability to securely handle their financial transactions.

Competitive Advantage

Organizations that achieve and maintain PCI DSS compliance can gain a competitive advantage over their noncompliant counterparts. Compliance signals to customers, partners, and stakeholders that the organization is committed to maintaining a high level of security, which can help attract new business and enhance the organization's reputation in the marketplace.

Business Continuity

Compliance with PCI DSS helps ensure that organizations have implemented robust security controls and processes, which contribute to the overall resilience and continuity of the business. In the event of a security incident or data breach, organizations that are PCI DSS compliant are better prepared to respond, recover, and minimize the potential impact on their operations and reputation.

PCI DSS Requirements

PCI DSS comprises 12 requirements organized into six control objectives designed to ensure that all organizations that process, store, or transmit credit card information maintain a secure environment. By adhering to these requirements, organizations can ensure the security of cardholder data and maintain a secure environment.

Build and Maintain a Secure Network and Systems

1.1 Install and maintain a firewall configuration to protect cardholder data.

  • Establish and document firewall and router configuration standards.
  • Implement a formal process for approving and testing all external network connections.
  • Ensure that security policies and operational procedures for managing firewalls are documented and followed.

1.2 Do not use vendor-supplied defaults for system passwords and other security parameters.

  • Change default passwords, remove unnecessary default accounts, and disable unnecessary services.
  • Implement security features for system components, such as encryption and strong authentication.
  • Maintain an inventory of system components and ensure proper configuration management.

Protect Cardholder Data

2.1 Protect stored cardholder data.

  • Limit the storage of sensitive cardholder data and follow data retention policies.
  • Encrypt cardholder data using strong cryptography techniques.
  • Implement proper key management procedures, including key storage and distribution.

2.2 Encrypt the transmission of cardholder data across open, public networks.

  • Use strong encryption and secure protocols for transmitting cardholder data over public networks.
  • Do not send unencrypted sensitive information via end-user messaging technologies, such as email or instant messaging.

Maintain a Vulnerability Management Program

3.1 Protect all systems against malware and regularly update antivirus software or programs.

  • Deploy antivirus software on all systems commonly affected by malware.
  • Ensure that antivirus mechanisms are actively running and can’t be disabled by users.
  • Regularly update antivirus signatures and perform periodic scans.

3.2 Develop and maintain secure systems and applications.

  • Establish a process for identifying and assessing security vulnerabilities in system components.
  • Install security patches and updates in a timely manner.
  • Follow secure coding guidelines and implement a secure software development lifecycle (SDLC).

Implement Strong Access Control Measures

4.1 Restrict access to cardholder data by business need-to-know.

  • Implement role-based access controls and enforce the principle of least privilege.
  • Establish a process for granting and revoking access to cardholder data.
  • Document and communicate access control policies and procedures.

4.2 Identify and authenticate access to system components.

  • Assign a unique ID to each person with access to system components.
  • Use strong authentication methods, such as complex passwords, multifactor authentication, or biometrics.
  • Implement proper password management practices, including periodic password changes and storage requirements.

4.3 Restrict physical access to cardholder data.

  • Implement physical access controls to restrict unauthorized access to facilities and sensitive areas.
  • Maintain visitor logs and monitor access to restricted areas.
  • Properly dispose of media containing cardholder data, including shredding, degaussing, or secure deletion.

Regularly Monitor and Test Networks

5.1 Track and monitor all access to network resources and cardholder data.

  • Implement automated audit trails for all system components to record user activities.
  • Regularly review logs and security events for signs of unauthorized activity.
  • Establish and follow procedures for log retention and review.

5.2 Regularly test security systems and processes.

  • Perform vulnerability scans and penetration tests regularly and after significant changes.
  • Test intrusion detection and prevention systems, file integrity monitoring tools, and other security measures.
  • Document and maintain a formal incident response plan that includes roles, responsibilities, and communication strategies.

Maintain an Information Security Policy

6.1 Establish, publish, maintain, and disseminate a comprehensive information security policy.

  • Develop a formal security policy that addresses all PCI DSS requirements and is approved by executive management.
  • Ensure that the policy is communicated to all relevant personnel and is regularly reviewed and updated.
  • Establish supporting policies and procedures, such as acceptable use, access control, and incident response, to provide guidance on implementing the security policy.

6.2 Develop and maintain risk assessment processes.

  • Conduct regular risk assessments to identify and evaluate threats and vulnerabilities to cardholder data.
  • Implement risk mitigation strategies to address identified risks.
  • Review and update risk assessments at least annually or whenever significant changes occur.

6.3 Implement security awareness training and education programs.

  • Provide security awareness training to all personnel upon hire and at least annually.
  • Include topics such as PCI DSS requirements, security policies, and incident response procedures.
  • Regularly update training content to address emerging threats and changes in the environment.

Technical Best Practices for PCI DSS Compliance

Security Information and Event Management (SIEM)

Organizations can enhance PCI DSS compliance with the implementation of security information and event management (SIEM) technology. SIEM effectively monitors the cardholder data environment (CDE) by collecting, analyzing, and correlating security events and logs from multiple sources within the organization's infrastructure. Continuous monitoring helps identify potential security threats, unauthorized access, and policy violations in real-time, enabling swift response to security incidents.

Network Segmentation

Organizations can minimize the scope of compliance efforts by isolating systems that store, process, or transmit cardholder data from other parts of the network. By implementing network segmentation, they reduce the number of systems subject to PCI DSS requirements.

Proper segmentation requires strong access controls, firewall rules, and continuous monitoring to ensure the separation and security of the cardholder data environment. In adhering to this best practice, organizations restrict the exposure of cardholder data and lower the risk of data breach.

Remote Access in PCI DSS

PCI DSS provides guidelines for remote access to ensure the security of cardholder data when connecting to an organization's network remotely. Key requirements include:

  • Implementing strong authentication mechanisms, such as multifactor authentication (MFA), for all remote access.
  • Encrypting remote connections using secure protocols, such as TLS or IPsec VPN.
  • Restricting remote access to only those users and systems that require it for their job functions.
  • Regularly monitoring and reviewing remote access logs to detect and respond to potential security incidents.
  • Ensuring that remote access software is kept up to date and protected against known vulnerabilities.

By following these guidelines, organizations can maintain a secure remote access environment and reduce the risk of unauthorized access to cardholder data.


Tokenization replaces sensitive cardholder data with a unique, nonsensitive identifier called a token. The original cardholder data is securely stored in a centralized, protected database, while the token is used for processing transactions. This PCI DSS standard reduces the risk of data breaches by limiting the exposure of sensitive cardholder data in the payment processing environment. In the event of a security breach, attackers only have access to the tokens, which are useless without the corresponding original data.

File Integrity Monitoring (FIM)

Monitoring and detecting unauthorized changes to critical files, system configurations, and application components, file integrity monitoring (FIM) identifies modifications to files. FIM then alerts administrators to potential security incidents, protecting cardholder data by ensuring the integrity of systems within the CDE. Implementing FIM enables organizations to detect unauthorized access, malware infections, or configuration errors that could compromise the security of sensitive payment card information.

Preparing for a PCI DSS Assessment

Preparing for a PCI DSS assessment involves a series of steps to ensure that an organization has implemented the necessary security controls and processes to protect cardholder data and maintain a secure environment.

Understand the PCI DSS Requirements

Familiarize yourself with the 12 requirements and six control objectives outlined by PCI DSS. A clear understanding of the security controls and processes will position you to achieve compliance.

Determine the Scope of the Assessment

Identify all system components, processes, and personnel that interact with or have access to cardholder data, including network devices, servers, applications, databases, and third-party service providers. Defining the scope ensures that all relevant areas are covered during the assessment.

Conduct a Gap Analysis

Evaluate the organization's current security posture against the PCI DSS requirements to identify gaps or areas of noncompliance. To determine where improvements are needed, review security policies, procedures, technical controls, and documentation.

Remediate Identified Gaps

Develop and implement a plan to address the gaps identified during the gap analysis. The plan may involve updating security policies, implementing new technologies or processes, and providing training to employees. Ensure that remediation efforts are documented and tracked.

Develop and Maintain Documentation

Creating and maintaining comprehensive documentation is essential to demonstrate the organization's compliance with PCI DSS requirements. The documentation should encompass security policies, procedures, network diagrams, data flow diagrams, risk assessments, incident response plans, and training records.

Implement and Monitor Security Controls

Ensure that security controls are properly implemented, monitored, and maintained. Establish processes for regular review and updates of security controls, as well as ongoing monitoring of system components and access to cardholder data.

Conduct Regular Security Testing

Perform vulnerability scans, penetration tests, and other security assessments to validate the effectiveness of security controls and identify potential weaknesses. Address any identified vulnerabilities in a timely manner.

Establish an Incident Response Plan

Develop a formal incident response plan that outlines the roles, responsibilities, and procedures for detecting, containing, and recovering from security incidents. Regularly review and update the plan and provide training to relevant personnel.

Train Employees and Raise Security Awareness

Provide ongoing security awareness training to employees to ensure they are familiar with PCI DSS requirements, the organization's security policies, and their roles and responsibilities in protecting cardholder data.

Engage a Qualified Security Assessor (QSA) or Internal Security Assessor (ISA)

Choose a QSA or ISA to perform the PCI DSS assessment. Ensure they have the necessary qualifications and experience to evaluate the organization's compliance with PCI DSS requirements.

Prepare for the Assessment

Collaborate with the QSA or ISA to schedule the assessment, provide necessary documentation, and facilitate access to relevant systems, personnel, and facilities.

Review and Address Assessment Findings

After the assessment, review the findings with the QSA or ISA and develop a plan to address any areas of noncompliance. Implement the necessary changes and provide evidence of remediation to the assessor.


A service provider in PCI DSS is an organization that processes, stores, or transmits cardholder data on behalf of merchants or other service providers. Examples include payment gateways, data centers, and managed security providers. Service providers play a crucial role in maintaining the security of cardholder data by adhering to PCI DSS requirements. They must implement appropriate security controls, undergo regular PCI DSS assessments, and provide evidence of compliance to their clients and acquiring banks.
Merchants, as entities that accept payment cards for goods or services, have several responsibilities in PCI DSS. They must maintain a secure environment for processing, storing, and transmitting cardholder data by implementing the necessary security controls outlined in the PCI DSS requirements. Merchants are also responsible for ensuring that any third-party service providers they engage with are PCI DSS compliant. Additionally, they must complete a Self-Assessment Questionnaire (SAQ) or undergo a full PCI DSS assessment, depending on their transaction volume and payment processing methods.

The Payment Card Industry Security Standards Council (PCI SSC) is an independent organization established by major payment card brands to develop and manage security standards for the payment card industry. The PCI SSC is responsible for maintaining and updating:

  • PCI Data Security Standard (PCI DSS)
  • Payment Application Data Security Standard (PA-DSS)
  • Point-to-Point Encryption (P2PE) standard

The council also provides training and certification programs for security professionals, such as Qualified Security Assessors (QSAs) and Internal Security Assessors (ISAs). The primary role of the PCI SSC is to ensure the security of cardholder data and promote the adoption of robust security controls across the payment ecosystem.

The PA-DSS is a set of security requirements established by the PCI SSC for software vendors that develop payment applications. These requirements aim to ensure that payment applications maintain a secure environment for processing, storing, and transmitting cardholder data. Compliance with PA-DSS helps prevent security breaches and reduces the risk of payment card fraud. Software vendors must submit their payment applications for validation by a PA-QSA (Payment Application Qualified Security Assessor) to verify that they meet the PA-DSS requirements and maintain a listing on the PCI SSC's list of validated payment applications.
Point-to-point encryption (P2PE) is a security technology that encrypts cardholder data at the point of interaction (e.g., card swipe, dip, or tap) and keeps it encrypted throughout its journey in the payment processing system. P2PE uses strong cryptographic algorithms and secure encryption keys to protect sensitive data, ensuring that even if the data is intercepted, it remains unreadable to unauthorized parties. Decryption of the data occurs only within a secure decryption environment, typically at the payment processor or acquiring bank's end.
A QSA is a professional certified by the PCI SSC to perform PCI DSS assessments on merchants and service providers. QSAs have extensive knowledge of the PCI DSS requirements, as well as experience in information security, risk assessments, and audit procedures. They are responsible for evaluating an organization's security posture, identifying gaps in compliance, and providing guidance on implementing security controls to protect cardholder data.
The Internal Security Assessor (ISA) program is a certification offered by the PCI SSC to train and qualify individuals within an organization to perform internal PCI DSS assessments. The program aims to enhance an organization's understanding of PCI DSS requirements and improve its internal security practices. ISAs are responsible for evaluating their organization's compliance with PCI DSS, identifying security gaps, and recommending remediation measures. By having an ISA within the organization, businesses can maintain a proactive approach to security and stay up to date with the latest PCI DSS requirements.
A Report on Compliance (ROC) is a formal document produced by a QSA or an ISA after conducting a PCI DSS assessment. The ROC details the organization's compliance status, identifies any gaps or areas of noncompliance, and provides a roadmap for remediation. It serves as evidence that the organization has undergone a comprehensive assessment of its security controls and is either compliant with the PCI DSS requirements or working toward compliance. The ROC is submitted to acquiring banks and payment brands to demonstrate the organization's commitment to protecting cardholder data.

Completing a Self-Assessment Questionnaire (SAQ) involves several steps. First, determine the appropriate SAQ type for your organization based on the payment processing methods used. Next, thoroughly review the SAQ to understand the PCI DSS requirements applicable to your organization.

Conduct a self-assessment to evaluate your organization's security controls, policies, and procedures against the requirements listed in the SAQ. Document any gaps or areas of noncompliance and develop a remediation plan to address them. Complete the SAQ by providing accurate responses to each question, then prepare the Attestation of Compliance (AOC) to confirm your organization's compliance status. Finally, submit the completed SAQ and AOC to the required parties, such as acquiring banks and payment brands.

The Attestation of Compliance (AOC) is a formal document that accompanies the Self-Assessment Questionnaire (SAQ) or Report on Compliance (ROC) and serves as a declaration of an organization's PCI DSS compliance status. It’s completed and signed by an authorized representative of the organization, such as an executive officer, and attests to the accuracy and completeness of the information provided in the SAQ or ROC. The AOC is submitted to acquiring banks, payment brands, or other relevant parties as evidence of the organization's commitment to protecting cardholder data and maintaining PCI DSS compliance.
The cardholder data environment (CDE) encompasses all components, systems, and processes within an organization that store, process, or transmit cardholder data or sensitive authentication data. The CDE includes hardware, such as servers, storage devices, and network devices; software, such as applications, databases, and operating systems; and personnel with access to cardholder data. Additionally, the CDE covers physical locations, security controls, and third-party service providers involved in handling sensitive payment card information. Identifying and securing the CDE is crucial for maintaining PCI DSS compliance and protecting cardholder data from potential security breaches.

Compensating controls are alternative security measures that organizations can implement when they can’t meet a specific PCI DSS requirement due to technical constraints or other legitimate business reasons. Compensating controls must provide an equivalent level of security to the original requirement and effectively mitigate the risk associated with noncompliance.

Organizations using compensating controls must document their rationale, the specific controls implemented, and how they effectively address the risk. During a PCI DSS assessment, QSAs or ISAs will evaluate the effectiveness of compensating controls and determine if they adequately maintain the security of cardholder data.

Secure Sockets Layer (SSL) and Transport Layer Security (TLS) are cryptographic protocols designed to provide secure communication over a computer network. SSL is the predecessor of TLS, and both protocols enable data encryption, authentication, and data integrity. TLS, though, offers improved security features, including stronger encryption algorithms and enhanced protection against various attacks.

Due to known vulnerabilities in SSL, it has been deprecated, and the use of TLS is now considered the industry standard. PCI DSS requires the use of TLS 1.2 or higher to ensure secure communication and protect cardholder data during transmission.