Every vulnerability in software can serve as a gateway for cybercriminals; the PCI SSF (Software Security Framework) sets a new benchmark in the protection of payment systems.
The PCI SSF is the PCI Security Standards Council’s (PCI SSC) response to the ongoing evolution of payment technologies. It has replaced the previous PA-DSS (Payment Application Data Security Standard), which has now been retired. The principal aim of the PCI SSF is to ensure that software processing payment data is designed and maintained with contemporary threats in mind, such as supply chain attacks and zero-day exploits.
The key difference between PCI SSF and PA-DSS?
While PA-DSS focused on ‘frozen’ versions of software, PCI SSF requires continuous vulnerability monitoring—even post-certification. This means that vendors must have processes in place to respond to emerging threats (for example, through updates).
The PCI SSF comprises two components:
- Secure Software Standard – requirements relating to the software itself (such as data encryption and access control).
- Secure Software Lifecycle Standard (SLC) – guidelines for software vendors to integrate secure practices and processes throughout the entire software development and maintenance lifecycle.
Although both standards address security, their scope and objectives differ—and it is precisely these differences that determine which standard is pivotal for your organisation. In this article, we explain what the PCI Secure Software Standard and the PCI Secure Software Lifecycle (SLC) Standard entail. We also indicate their intended audiences and provide guidance on effective implementation to minimise risk and maximise business value.
PCI Secure Software Standard: A Breakthrough in Payment Software Security
Who requires the PCI Secure Software Standard?
- Providers of payment software (e.g. developers of POS systems, e-commerce platforms).
- Technology integrators implementing payment APIs.
- Financial institutions developing their own transaction processing applications.
PCI Secure Software Lifecycle (SLC): Security Embedded in the Software Lifecycle
The PCI Secure Software Lifecycle (SLC) is the second pillar of the PCI SSF, but is often treated as a distinct standard. It concerns not the code itself, but the methodology of its development. Its objective is to integrate security practices at every stage of software development—from design through to maintenance.
Who is PCI SLC intended for?
- Development teams creating payment software.
- Cloud providers offering SaaS solutions for the financial sector.
- Organisations modifying off-the-shelf payment applications (e.g. adapting them to local regulations).
The main requirements of PCI SLC include:
- Implementation of automated security testing within the CI/CD process.
- Regular architectural reviews for threats (e.g. threat modelling).
- Developer training in secure coding (at least annually).
PCI Secure Software Standard vs PCI Secure Software Lifecycle (SLC): Where Does the Difference Lie?
Although the two standards are interrelated, they differ in both scope and objective:
| Criterion | PCI Secure Software Standard | PCI SLC |
| Objective | Certification of the security of the finished software | Certification of software development processes |
| Focus | ‘Product’ – does the application meet security requirements? | ‘Process’ – does the company have a methodology for secure code development? |
| For whom? | Software vendors | Development teams and vendors |
| Key requirements | Data encryption, access control, vulnerability management | Training, security testing, risk management in SDLC |
Practical example:
Company X provides an e-commerce platform integrated with a payment gateway. In order to sell its product to banks, it requires PCI SSF – Secure Software Standard certification. However, to maintain the certificate, it must also implement PCI SLC—i.e. document that its development processes include, for example, code reviews for OWASP Top 10 vulnerabilities.
Implementing PCI Secure Software Standard and SLC: Challenges and Solutions
Implementation of these standards is seldom straightforward. From our experience at Patronusec, the most common barriers are:
- Lack of secure coding expertise – many development teams still view security as a ‘burden’ rather than an integral part of the process.
- Cost of tools – automating tests (SAST, DAST) requires investment in solutions such as Checkmarx or Veracode.
- Complexity of documentation – PCI SLC, for example, requires mapping all development activities to the standard’s requirements.
How do we address this?
At Patronusec, we have developed a collaborative model that includes:
- Preliminary audit – identifying gaps between current practices and the requirements of the PCI Secure Software Standard and SLC.
- Support in tool selection – assisting in the choice of solutions tailored to the organisation’s budget and scale.
- Bespoke training – e.g. threat modelling workshops for architects.
Why Is PCI SSF an Investment Rather Than a Cost?
According to the 2023 Verizon report, nearly half of data breaches in the financial sector result from software flaws. Implementing the PCI Secure Software Standard and SLC Standard minimises this risk, but also:
- Boosts competitiveness – certified software is more frequently chosen by banks and payment institutions.
- Shortens due diligence – auditors are quicker to approve solutions compliant with PCI SSC.
- Facilitates compliance with GDPR and PSD2 – many requirements overlap with these standards.
How to Get Started?
If you are considering which standard is critical for your organisation, ask yourself two questions:
- Do you supply payment software to other entities? → PCI Secure Software Standard.
- Do you develop or modify such software? → PCI SLC Standard.
At Patronusec, we have conducted over 120 PCI SSF audits for companies in Central and Eastern Europe. Our approach is based on:
- In-depth code and architecture analysis – we do not limit ourselves to checklists.
- Collaboration with development teams – we demonstrate how to implement standards without slowing down releases.
- Ongoing post-certification support – including vulnerability monitoring based on MITRE CVE.
Do you require assistance with PCI Secure Software Standard and SLC Standard certification? Contact us to arrange a complimentary consultation with our experts. We will analyse your needs and propose an implementation pathway that not only meets PCI SSC requirements but also strengthens your product’s market position.
Patronusec is a leading provider of cybersecurity services, specialising in PCI DSS, PCI Secure Software Standard, and Secure SLC Standard audits. Our solutions help companies secure payment systems and meet regulatory requirements.
