Secure Element Chip Certification: Understanding Tangem’s EAL 5+ Security Standards

A hardware wallet’s security depends partly on claims and partly on verifiable proof. When a manufacturer states that a device’s private keys are protected by a secure element chip, the statement means little without independent assessment. Tangem’s cards and rings embed secure element chips certified to EAL 5+ (Evaluation Assurance Level 5 Plus), a standard issued by Common Criteria, an international framework that assesses cryptographic hardware against attack scenarios and design rigor. Understanding what that certification covers—and what it does not—is essential for evaluating whether a cold wallet crypto solution genuinely protects keys or merely appears to.

The distinction matters because security certifications operate within defined scopes. EAL 5+ does not mean «unhackable.» It means that an independent laboratory has tested the hardware design, manufacturing controls, and resistance to specific attacks under specified conditions. A Tangem wallet relies on that certification as one component of a broader security architecture that also includes firmware, application-level protocols, user behavior, and backup procedures. Comparing EAL 5+ to competitor certifications or to uncertified solutions requires understanding what each standard actually tests and where the real-world security boundaries lie.

What EAL 5+ certification actually covers

Common Criteria is a framework maintained by international governments and used to evaluate information security products. The framework assigns assurance levels from EAL 1 (lowest) to EAL 7 (highest), each with defined testing requirements and evidence standards. EAL 5+ represents evaluation at a level where the manufacturer must provide substantial design documentation, threat modeling, source code reviews, and evidence of vulnerability analysis. An accredited laboratory conducts independent penetration testing and reviews the evaluation results before issuing certification.

For hardware-based cryptographic operations, EAL 5+ testing specifically examines the secure element’s resistance to side-channel attacks, such as differential power analysis (timing the power consumption during cryptographic operations) and electromagnetic emission analysis (reading electromagnetic radiation leaked by the processor). The certification scope also covers physical tampering resistance, including attempts to read memory contents through voltage stress, focused beam attacks, or abrasive material removal. The Tangem wallet’s secure element chip must demonstrate that such attacks either fail to extract the private key or require resources and expertise that exceed the threat model’s defined assumptions.

Importantly, certification does not cover the entire device ecosystem. EAL 5+ applies to the secure element hardware and its internal cryptographic library. The mobile application, network communication, user interface, operating system of the phone running the Tangem mobile app, and cloud backup components fall outside the secure element’s physical protection. A compromise at the application or OS level could potentially expose transaction details, signing requests, or address information without touching the certified hardware itself. The hardware protects the key; the application must protect the context in which the key is used.

A certified secure element also operates under specific environmental assumptions. Testing typically covers a temperature range, voltage range, and operational frequency range. Attacks conducted outside those parameters—such as cryogenic attacks or extreme electromagnetic pulse conditions—may not be formally assessed. Tangem’s design documentation should specify which attack vectors were tested and under what conditions. Manufacturers sometimes emphasize what certification covers while being silent about what was explicitly excluded, so reading the actual certification certificate is more informative than marketing summaries.

Common Criteria levels and what they mean in practice

The gap between EAL 3 and EAL 5+ is substantial. At EAL 3, the manufacturer must provide informal design documentation and basic testing, but vulnerability analysis is limited. At EAL 4, formal design methods begin to appear and more rigorous testing is required. EAL 5+ demands that the manufacturer employ formal verification methods in design, conduct systematic penetration testing, and provide evidence of vulnerability analysis before the evaluation laboratory even begins. The laboratory then independently repeats testing and confirms the manufacturer’s claims.

EAL 6 and EAL 7 exist but are rarely sought for consumer hardware. EAL 6 requires formal verification of the security policy and protection profiles, along with evidence of countermeasures to advanced attacks. EAL 7 demands formal verification of the entire implementation and is typically pursued only for military or national-security applications. The cost and time required to achieve EAL 7 are generally not justified for a wallet, and the incremental security benefit for consumer use cases is marginal compared to EAL 5+.

Comparing Tangem wallet certification to competitors requires examining their respective assurance levels and testing scope. Some competitors claim EAL 5+ certification for their hardware, while others cite lower levels or rely on security audits conducted by private firms rather than accredited Common Criteria laboratories. A private security audit is valuable, but it does not follow a standardized methodology or undergo the same independent validation as Common Criteria. A hardware wallet certified to EAL 5+ by an accredited laboratory has passed a more rigorous and reproducible evaluation than one that has undergone only internal or contracted audits.

The Common Criteria framework also requires that the certification be renewed periodically and that the manufacturer maintain a vulnerability disclosure policy. If a new attack method emerges, the manufacturer must assess whether the secure element remains compliant or whether updated protections are needed. This ongoing maintenance distinguishes certification-backed products from devices where security is a historical claim rather than a managed commitment.

How secure element chips protect private keys from side-channel attacks

A private key stored in a traditional computer’s memory is vulnerable to a range of attacks that do not require breaking the cryptography. Side-channel attacks exploit the physical properties of the hardware executing the cryptographic operation. When a processor multiplies numbers or compares bytes, it consumes power and emits electromagnetic radiation in patterns that can leak information about the data being processed. A secure element chip is designed with countermeasures that make such leakage either impossible to measure or impossible to correlate with the key material.

Differential power analysis (DPA) is a well-known side-channel attack where an attacker collects many power traces as the device processes different inputs, then uses statistical methods to identify which data values are being processed. A secure element includes power analysis countermeasures such as random delay injection, which inserts random idle cycles into the computation; random masking, which XORs the sensitive data with random values during processing; or dual-rail logic, which processes complementary data values in parallel to equalize power consumption. These techniques do not prevent the operation; they make the power trace indistinguishable from noise.

Electromagnetic analysis operates similarly, but instead of measuring power consumption, it measures the electromagnetic field radiated by the processor. A secure element’s shielding and electromagnetic hardening techniques aim to attenuate the field strength or randomize its characteristics. The Tangem wallet’s secure element is embedded in a card or ring with shielding materials that reduce the signal available to an external probe, raising the cost and complexity of a successful attack.

Fault injection attacks intentionally induce errors in the computation to leak information. By subjecting the hardware to voltage spikes, frequency changes, or laser pulses, an attacker can cause a cryptographic operation to produce an incorrect result in a controlled way. That incorrect result, combined with the correct one and knowledge of the operation, can reveal the key. A secure element includes fault detection mechanisms, such as redundant computations or parity checks, that trigger a protective shutdown if an anomaly is detected.

The Tangem wallet’s EAL 5+ certification demonstrates that these countermeasures have been evaluated against standard attack methodologies. However, the evaluation is conducted under defined laboratory conditions. An attacker with unlimited time and resources, access to specialized equipment (such as focused ion beam tools or cryogenic chambers), and updated knowledge of the secure element’s design might eventually find weaknesses. The certification does not claim invincibility; it claims that the effort and cost required to mount a successful attack exceed what a typical attacker would invest in a consumer device.

Scope boundaries: What the secure element does not protect

One common misunderstanding is that a certified secure element makes the entire device secure. In reality, the certification applies narrowly to the hardware component and the cryptographic operations it performs. The Tangem wallet stores the private key in the secure element, which is good. The transaction the user wants to sign, the address they are sending to, and the amount they are authorizing are typically displayed on the mobile device’s screen, processed by the phone’s operating system, and handled by the application.

A compromised phone or tablet running the Tangem mobile app could display an incorrect address or amount while the secure element signs the transaction the user intended. The phone could be infected with malware that intercepts the transaction details before they are sent to the secure element for signing, modifies them, and then sends the modified version to the hardware. The secure element would faithfully sign the malware-provided data. From the hardware’s perspective, nothing is amiss; the operation is valid. The user has authorized a transaction to a wrong address because the information displayed was false.

This is not a theoretical risk. Hardware wallet users have repeatedly lost funds by scanning malicious QR codes or trusting incorrect address displays. The secure element protects the key from exposure, but it does not protect the user from approving a transaction to an attacker-controlled address. Cold wallet crypto security therefore depends on both the hardware and the application environment. A Tangem wallet is only as secure as the phone on which it runs and the user’s ability to verify transaction details through an independent channel.

Network security also falls outside the secure element’s scope. When the mobile app broadcasts a signed transaction to the blockchain, that message travels over the internet through routers, ISPs, and potentially public WiFi networks. Malicious network actors cannot forge the cryptographic signature (the secure element prevents that), but they could potentially delay the transaction, observe its timing, or correlate it with other network traffic. For most users, these risks are acceptable. For users with higher threat models, additional network protections such as Tor or VPN may be appropriate, independent of the secure element’s certification level.

Comparing secure element certifications across hardware wallet manufacturers

The hardware wallet market includes devices with varying assurance levels. Some competitors employ secure elements certified to EAL 4, which is lower than the EAL 5+ that Tangem wallet products achieve. EAL 4 certified hardware still provides substantial protection against side-channel and fault attacks, but the testing is less rigorous and the design verification is less formal than EAL 5+. For many users, EAL 4 is adequate; for users managing high-value portfolios or operating in adversarial environments, EAL 5+ provides measurably better assurance.

Other competitors do not pursue Common Criteria certification at all. Instead, they conduct security audits by private cryptography firms or employ self-developed security validation methods. These approaches are not inherently weak, and some private audits are very thorough. However, they lack the standardization and independent oversight that Common Criteria provides. A private audit is evaluated on the auditor’s reputation and methodology; a Common Criteria certification is evaluated against a published standard with accredited laboratories enforcing consistency.

Some manufacturers claim certification for certain components but not the full device. For example, a chip manufacturer might certify the processor, while the system integrator (who designs and manufactures the wallet) does not pursue certification for the complete implementation. The Tangem wallet’s approach is to certify the secure element as the central component, which covers the most critical attack surface: the hardware that holds the key and performs cryptographic operations.

The cost of pursuing EAL 5+ certification is significant, typically ranging from hundreds of thousands to millions of dollars depending on the product complexity and the laboratory’s hourly rates. Smaller or lower-volume hardware wallet manufacturers may not justify this investment, instead relying on security audits. Tangem’s scale and market positioning have allowed the company to absorb this cost, which is one reason why the EAL 5+ certification is a credible differentiator rather than a baseline expectation across the entire market.

The role of firmware and application in the complete security model

The secure element chip is secure, but it does not operate in isolation. Firmware running inside the secure element implements the cryptographic protocols, enforces key access policies, and manages the interface between the card and the mobile application. Firmware vulnerabilities can undo the benefits of hardware certification. A programming error in the firmware could allow a key derivation function to accept invalid inputs, skip security checks, or leak intermediate values during computation.

The Tangem wallet addresses firmware security through a combination of design practices and verification. The firmware is typically kept minimal, with complex logic deferred to the mobile application where updates are easier to deploy. Regular firmware updates are delivered through the Tangem mobile app, and users are prompted to apply them. Firmware running inside a certified secure element is reviewed more thoroughly than firmware on an uncertified device, but the review process for updates may be less extensive than the original EAL 5+ certification.

The mobile application itself is the user’s primary interface to the hardware. The application must accurately display transaction details, correctly format data sent to the secure element for signing, and securely manage the connection to the hardware via NFC. An application with poor security practices—such as logging transaction details to a file, storing addresses in plain text, or using insecure network protocols—can expose user information regardless of the hardware’s certification level.

Tangem’s design philosophy separates concerns between the secure element (which holds the key and never exposes it) and the mobile application (which handles user interaction and network communication). This division of responsibility means that the secure element does not need to implement a full wallet interface, which keeps firmware simpler and more verifiable. The application can be updated frequently to patch vulnerabilities or add features without requiring secure element firmware updates, which would be more complex and slower to deploy.

Evaluating tangem wallet’s certification in context of your threat model

EAL 5+ certification is meaningful for specific threat scenarios and less relevant for others. If your primary concern is that malware on your computer will steal your private key, a Tangem wallet provides strong protection because the key never leaves the secure element and never travels over USB or any internet connection. If your concern is that a sophisticated attacker with laboratory equipment will extract your key through side-channel attacks, EAL 5+ certification means the device has been tested against known attacks and countermeasures have been verified.

If your threat model includes an attacker who can physically disassemble the device and perform focused ion beam attacks or other advanced semiconductor reverse engineering, EAL 5+ certification does not guarantee protection. The testing for EAL 5+ does not typically cover these extreme attacks. That level of adversary is rare and typically associated with state-level actors targeting high-value targets.

If your primary concern is that you will lose your recovery phrase or forget your PIN, the secure element’s certification is irrelevant. User behavior and backup procedures determine whether you can recover your wallet in a disaster scenario. If your concern is that someone will shoulder-surf your PIN or photograph your recovery phrase, the hardware certification offers no protection. These social engineering risks are orthogonal to hardware security.

The most common and practical threat model for a Tangem wallet user is protection against remote theft. An attacker exploits vulnerabilities in the user’s computer or phone to install malware, which attempts to steal private keys. The EAL 5+ certified secure element directly addresses this threat by ensuring the key remains in the hardware and cannot be extracted through software attacks. For this scenario, the certification provides substantial real-world value.

Future certification developments and evolving attack methods

Common Criteria and secure element certifications are not static. As new attack methods emerge, the community develops new testing profiles and manufacturers update their designs. The Protection Profile for Secure Signature Creation Devices (specifically, the profiles related to cryptographic hardware) is regularly updated to reflect new threats. Manufacturers pursuing EAL 5+ or higher certifications in coming years may be required to demonstrate resistance to attacks that were not explicitly tested in earlier evaluations.

Post-quantum cryptography is an example of an emerging concern. As quantum computers become practical, the elliptic curve and RSA algorithms that currently protect cryptocurrency may become vulnerable. Manufacturers are beginning to incorporate post-quantum algorithms into secure elements, and future certification profiles may require resistance to attacks that simulate quantum computing capabilities. A cold wallet crypto solution like Tangem wallet will need to evolve to remain secure against these emerging threats.

Physical attack methods are also advancing. Focused ion beam techniques, electromagnetic fault injection, and advanced side-channel analysis are becoming more accessible outside of specialized laboratories. Future EAL certifications may incorporate higher standards for resistance to these attacks. Manufacturers that pursue certification updates demonstrate a commitment to maintaining security as the threat landscape evolves.

Users should periodically review whether their hardware wallet’s certification remains current and whether the manufacturer continues to publish security updates. An older device with outdated firmware may have been certified at a high level but could have accumulated vulnerabilities through new discoveries. Checking the tangem wallet security documentation and update history provides insight into how actively the manufacturer addresses emerging threats.