EUCLEAK side channel in Infineon ECDSA library reaches Trezor Safe 3 and Safe 5 chip

September 3, 2024TrezorLow

Who is affected

An attacker with physical access and laboratory equipment could, per NinjaLab, extract ECDSA keys from the OPTIGA Trust M chip used in the Trezor Safe 3 and Safe 5. Trezor states the recovery seed and funds are not at risk because that cryptography does not protect the wallet backup.

What happened

On 3 September 2024 NinjaLab published EUCLEAK, research by Thomas Roche describing an electromagnetic side-channel vulnerability in the ECDSA implementation of Infineon’s cryptographic library, caused by a non-constant-time modular inversion. The researchers demonstrated the attack on a YubiKey 5Ci and state that it also affects Infineon’s OPTIGA Trust M and OPTIGA TPM security microcontrollers. NinjaLab says the flaw went unnoticed for 14 years and lists crypto-currency hardware wallets among the systems built on the affected chips, while noting it had not checked whether the attack applies to them. MITRE assigned CVE-2024-45678.

According to the researchers, the attack requires physical access to the secure element, after which a few minutes of local electromagnetic measurements are enough to extract an ECDSA secret key. BleepingComputer adds that it needs extended physical access, specialised equipment and a high level of expertise in electronics and cryptography. NinjaLab states that Infineon has a patch for its cryptographic library.

Trezor’s documentation says the Trezor Safe 3 and Safe 5 use an OPTIGA Trust M (V3) secure element, which enforces the PIN, holds a secret that together with the PIN encrypts the keys on the main chip, and stores a certificate used for authenticity checks. On 4 September 2024 Trezor stated that it had been alerted to the vulnerability affecting the OPTIGA Trust M in the Safe 3 and Safe 5, that it cannot be used to extract the recovery seed because the affected cryptography is not involved in creating or protecting the device backup, and that funds remain secure. CriptoNoticias reports that Trezor also said the flaw could in theory allow its authenticity check to be bypassed, a counterfeit risk Trezor says other supply-chain measures mitigate.

None of the sources reports an update for the OPTIGA Trust M in devices already sold; Trezor said it would share any new findings.

Timeline: NinjaLab announced the research and submitted the paper to the IACR ePrint archive on 3 September 2024; Trezor published its statement on 4 September 2024.

Sources

Independent reporting and research this entry was checked against.

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Fault Injection

Fault injection disturbs a chip's voltage, clock or electromagnetic environment so that it skips a security check or leaks data.

Side-Channel Attack

A side-channel attack in cryptocurrency and blockchain targets indirect information, like power usage or timing, to extract sensitive data from a system or device.

Secure Element

A secure element is a tamper-resistant chip built to store secrets and resist physical attacks such as side-channel analysis and fault injection.

Evil Maid Attack

An evil maid attack is a physical security threat where an attacker gains temporary unsupervised access to a hardware wallet to tamper with it, install malicious firmware, or extract private keys.

Cite this entry

WalletInsights. “EUCLEAK side channel in Infineon ECDSA library reaches Trezor Safe 3 and Safe 5 chip”. Hardware wallet security incident tracker. Last verified November 3, 2026. https://walletinsights.io/en/security-incidents/eucleak-infineon-side-channel-trezor-safe-2024/

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