P2PE vs E2EE vs NESA – 3 Approaches to Payment Encryption and Their Impact on PCI DSS Scope

What is the difference between P2PE, E2EE and NESA? P2PE (Point-to-Point Encryption) is card data encryption validated by PCI SSC and published on its official list of solutions. E2EE (End-to-End Encryption) uses a similar architecture but carries no PCI validation. NESA (Non-listed Encryption Solution Assessment) is an assessment of an E2EE solution performed by a P2PE QSA against the PCI P2PE Standard, without any PCI SSC listing.

Canonical definition: NESA (Non-listed Encryption Solution Assessment) is an evaluation of a non-validated card data encryption solution, performed by a P2PE QSA against the PCI P2PE Standard, documenting gaps against the standard and the solution’s impact on a merchant’s PCI DSS scope.

The choice between these three approaches determines whether a merchant completes the 21-question SAQ P2PE or negotiates scope with their acquirer, and, for a solution provider, the cost of market entry and the strength of the sales argument.

P2PE vs E2EE vs NESA – key takeaways:

1. Only solutions validated and listed by PCI SSC entitle a merchant to complete SAQ P2PE, which contains 21 questions (SAQ P2PE v4.0, PCI SSC document).
2. An E2EE solution may encrypt data in a technically identical way to P2PE, yet any PCI DSS scope reduction then depends entirely on the merchant’s acquirer.
3. NESA is neither a certification nor a listing – it is a document, prepared by a P2PE QSA, describing the solution’s gaps against the PCI P2PE Standard.
4. The current PCI P2PE Standard v3.2 (Jun 2025) covers 5 domains: from POI device management, through application security, to cryptographic key operations.
5. P2PE validation requires POI devices approved under the PCI PTS programme with SRED, plus HSMs meeting FIPS 140-2/140-3 Level 3 or PCI HSM in the decryption environment.
6. Patronusec, as an accredited QSA, advises both merchants selecting an encryption solution and solution providers preparing for P2PE validation or a NESA review.

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How does P2PE differ from E2EE?

P2PE differs from E2EE in formal status, not technical architecture. P2PE is a solution validated by a P2PE QSA against the PCI P2PE Standard and listed by PCI SSC. E2EE is any card data encryption from the point of acceptance to the point of decryption that has not undergone such validation. The consequences concern the merchant’s PCI DSS scope and who gets to decide it.

Both approaches pursue the same goal: card data is encrypted the moment it is read at the terminal and stays encrypted until it reaches a secure decryption environment, so the merchant’s systems never touch clear-text data. The difference lies in who confirms that the solution actually behaves the way the vendor claims.

For P2PE, that confirmation comes from an independent assessment by a P2PE QSA (a Qualified Security Assessor holding the additional P2PE qualification), a P-ROV (P2PE Report on Validation) accepted by PCI SSC, and a public entry on the list of Validated P2PE Solutions. For E2EE there is no such confirmation – the merchant and their acquirer rely on the vendor’s declarations or on assessments arranged privately.

A validated P2PE solution is the only class of encryption solution that automatically entitles a merchant to use SAQ P2PE – for E2EE solutions, any PCI DSS scope reduction must be individually accepted by the merchant’s acquirer.

The fix, in practical terms: if two vendors offer technically identical encryption but only one holds a PCI SSC listing, the merchant using the listed solution has a guaranteed simplified compliance route, while the other has to negotiate it case by case.

What is a validated P2PE solution and what does it give the merchant?

A validated P2PE solution is a complete set of hardware, software and processes that encrypts card data inside an approved POI device and decrypts it only in the provider’s secure environment, assessed against the 5 domains of the PCI P2PE Standard and listed by PCI SSC. A merchant using such a solution removes clear-text data from its environment.

The current PCI P2PE Standard v3.2 (Jun 2025) requires encryption to take place exclusively in POI devices approved under the PCI PTS programme with SRED (Secure Reading and Exchange of Data) enabled, and decryption plus key operations to occur in HSMs meeting FIPS 140-2/140-3 Level 3 or higher, or approved under PCI HSM. According to PCI SSC, v3.2 is a minor revision: validations performed against v3.0 and v3.1 remain valid, while the Council continues developing P2PE v4.0. The key artefact for the merchant is the PIM (P2PE Instruction Manual) – the document describing how to operate the terminals securely.

The merchant’s benefits are measurable:

• SAQ P2PE instead of SAQ D. A comparison of the official PCI SSC questionnaires for PCI DSS v3.2.1 shows the scale: SAQ D ran to 329 questions and SAQ P2PE to 33 – a reduction of nearly 90%. In the PCI DSS v4 edition (v4.0.1 is now in force) the SAQ P2PE was consolidated to 21 questions.
• No vulnerability scanning or penetration testing obligations within SAQ P2PE – those duties sit with the solution provider in its decryption environment.
• Lower breach impact. Data encrypted within SRED has no value to an attacker, because the keys never leave secure cryptographic devices.

The provider’s benefit is different but equally tangible: a PCI SSC listing is a sales argument that shortens every compliance conversation with merchants and acquirers. Instead of bespoke assessments, the provider points to a single public listing.

Patronusec Insight: In our project experience, merchants most often overpay not for the encryption solution itself, but for skipping the fine print of the listing before deployment. The PCI SSC listing specifies exact POI device models, application versions and configurations covered by the validation – deploying a terminal variant outside the listing (for example, a different firmware version) removes the right to SAQ P2PE, even though the merchant bought a “validated solution”. Before signing with a provider, compare the deployment offer against the listing line by line.

What is E2EE in payments and what are its limitations?

E2EE (End-to-End Encryption) in payments is the encryption of card data from the point of interaction to the point of decryption at a processor or gateway, delivered without validation against the PCI P2PE Standard. Many processors and terminal vendors offer E2EE, often as a standard element of their acquiring service.

The technical quality of E2EE solutions can be high – some of them predate the first version of the P2PE Standard (Sep 2011) and have run in production for years. The problem is not the cryptography but the absence of independent confirmation across three areas the P2PE Standard verifies in detail: key management (generation, distribution, injection), the device supply chain, and the security of the decryption environment.

For the merchant this has two consequences:

• Scope reduction is not automatic. The merchant cannot complete SAQ P2PE. Any reduction in applicable PCI DSS controls is decided by the acquirer based on its own risk assessment.
• The burden of proof sits with the merchant and the vendor. The QSA assessing the merchant’s environment must establish the PCI DSS boundary independently, because there is no listing to rely on.

For the vendor, however, E2EE brings real commercial advantages: no validation costs (a P2PE assessment is a project measured in months), freedom to change the solution without a delta assessment process, and faster time to market. It is a defensible choice when the vendor works mainly with a single acquirer that accepts the solution, or when the product is still maturing towards full validation.

E2EE and P2PE can use identical algorithms and architecture – the difference is that in P2PE every element of the solution has been confirmed compliant by an independent P2PE QSA, while in E2EE that confirmation is made (or not) by the acquirer.

What is NESA and when does it apply?

NESA (Non-listed Encryption Solution Assessment) is an evaluation of a non-validated encryption solution that a P2PE QSA performs against the PCI P2PE Standard, based on PCI SSC guidance published in 2016. The output is documentation of gaps against the standard and a recommendation on how the solution affects a merchant’s PCI DSS scope. NESA does not result in a PCI SSC listing.

According to the PCI SSC FAQ, the aim of a NESA is to identify the gaps between the solution and the PCI P2PE Standard and to show how use of the solution impacts a merchant’s PCI DSS assessment. The Council stresses that this is guidance only, not requirements, and that only listed solutions are fully validated against the standard.

The process works as follows: the solution provider engages a P2PE QSA, who completes the NESA template together with a P-ROV. The document set goes to merchants using the solution, who hand it to their own QSAs as input to their PCI DSS assessments. According to PCI Perspectives (the PCI SSC blog), NESA was intended for situations where a merchant uses an encryption solution that predates the P2PE Standard.

The key limitations of NESA:

• The merchant still cannot complete SAQ P2PE – SAQ eligibility criteria remain unchanged.
• Scope reduction must be accepted by the merchant’s acquirer – NESA is an argument, not a decision.
• NESA describes a point in time; without a PCI SSC oversight programme, nothing enforces continued compliance.

In market practice, NESA often serves as a transitional stage for providers working towards full P2PE validation: it lets them give merchants a documented argument in acquirer conversations in the meantime. It also grounds cost planning: NESA shows how far the solution is from full compliance before the vendor commits to a formal validation programme.

What benefits does each solution type give the provider, and what does it give the merchant?

Each of the three approaches distributes costs and benefits differently between provider and merchant. P2PE maximises the merchant’s benefit at the cost of the provider’s investment, E2EE minimises the provider’s costs at the price of the merchant’s uncertainty, and NESA sits in between.

Criterion	P2PE (validated)	NESA	E2EE (no assessment)
PCI SSC listing	Yes	No	No
Merchant’s SAQ	SAQ P2PE (21 questions in v4.0)	SAQ agreed with acquirer	SAQ agreed with acquirer (usually SAQ D or B-IP)
Who decides scope reduction	PCI SSC (via listing) + acquirer formally	Acquirer, based on the NESA document	Acquirer, based on vendor declarations
Assessment performed by	P2PE QSA (full P-ROV, PCI SSC acceptance)	P2PE QSA (NESA + P-ROV, no PCI SSC acceptance)	No formal assessment required
Maintenance cycle	3-year revalidation + annual attestation	No formal cycle	None
Main provider benefit	Sales argument accepted by every acquirer and merchant	Documented maturity, stepping stone to full validation	Low cost, fast time to market
Main merchant benefit	Minimal PCI DSS scope, no scans or pentests in SAQ	Possible scope reduction once the acquirer accepts	Real technical risk reduction without formal guarantees

For a solution provider, the decision comes down to the business model. If the solution is sold to many merchants working with different acquirers, P2PE validation pays for itself by eliminating case-by-case negotiations. If the vendor operates in a closed ecosystem with a single acquirer, well-documented E2EE may be enough.

The fix: the “P2PE or E2EE” question is really the question of who bears the cost of proving security – the provider once, or every merchant separately.

How do you choose between P2PE, E2EE and NESA?

The choice depends on three variables: the number of acquirers in the ecosystem, the solution’s maturity against the P2PE Standard, and whether PCI DSS scope reduction is part of the commercial offer. The decision trees below cover the most common scenarios.

Merchant’s perspective:

1. Is the solution on the PCI SSC list of Validated P2PE Solutions (in the exact configuration you are deploying)?
   • YES → you qualify for SAQ P2PE. Verify the deployment against the listing and follow the PIM.
   • NO → go to question 2.
2. Does the vendor hold a current NESA document from a P2PE QSA?
   • YES → pass the NESA to your QSA and acquirer; negotiate a reduced control set. SAQ P2PE remains unavailable.
   • NO → go to question 3.
3. Has the acquirer accepted scope reduction for this E2EE solution in writing?
   • YES → apply the agreed scope and retain the correspondence as evidence for the PCI DSS assessment.
   • NO → treat the environment as standard scope (usually SAQ D or a QSA assessment).

Provider’s perspective:

1. Do your customers settle with multiple acquirers, or do they expect SAQ P2PE?
   • YES → target full P2PE validation; consider NESA as an interim stage.
   • NO → go to question 2.
2. Does the solution already meet the core P2PE requirements (SRED-enabled POI devices, HSMs for decryption, Domain 5 key management)?
   • YES → a NESA will quickly document maturity and support sales until full validation.
   • NO → start with a gap analysis against the P2PE Standard before commissioning any formal assessment.

Patronusec performs a gap analysis of encryption solutions against the PCI P2PE Standard – the provider receives a domain-by-domain map of shortfalls and a realistic estimate of the route to NESA or full validation.

Myth vs fact: what do people get wrong about P2PE, E2EE and NESA?

MYTH: E2EE gives a merchant the same PCI DSS scope reduction as P2PE, because the encryption is identical.
FACT: SAQ P2PE eligibility requires a solution listed by PCI SSC. For E2EE, any reduction in controls must be individually accepted by the acquirer, and there is no guarantee it will be.

MYTH: NESA is a “P2PE light” certification that puts the solution on the PCI SSC list.
FACT: NESA ends with no listing and no PCI SSC acceptance. It is a P2PE QSA document describing gaps against the standard, which the merchant can pass to their QSA and acquirer.

MYTH: Deploying validated P2PE removes the merchant from PCI DSS entirely.
FACT: The merchant remains subject to PCI DSS – completing SAQ P2PE (21 questions) and staying responsible for, among others, physical terminal protection and following the PIM.

MYTH: If the solution is listed, every terminal configuration at the merchant is covered by the validation.
FACT: The listing covers specific POI models, firmware versions and applications. Deploying a variant outside the listing removes the merchant’s right to SAQ P2PE.

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FAQ – P2PE vs E2EE

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Recommended reading

A logical reading path for payment encryption:

1. P2PE (Point-to-Point Encryption): a guide to secure payment solutions – the foundation: how P2PE works and what a solution consists of.
2. PCI DSS compliance: navigating the scope without confusion – how encryption shapes the boundary of the CDE.
3. MPoC, SPoC and CPoC: a revolution in secure mobile payments – what happens when a smartphone becomes the terminal.
4. How much does PCI certification cost – the economics of formal assessments in the PCI ecosystem.

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Payment encryption and PCI DSS scope – free consultation

Patronusec, an accredited QSA, advises encryption solution providers and merchants on PCI DSS and PCI P2PE projects. If you are considering validating a solution or want to verify how encryption affects your compliance scope, book a free consultation.

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