Critical vulnerability of temporal collateral attack

Timing Phantom Attack (timing side-channel attack)

Bitcoin’s cryptographic operations represent one of the most dangerous and difficult-to-detect vectors for compromising private keys. Unlike classic exploits, this attack does not require system penetration or malicious code injection—it only requires monitoring the execution time of standard cryptographic operations to gradually recover sensitive data, including users’ private keys.

Morse Code of Time technique

The Shadow of Time works on the principle of cryptographic Morse code:

Each bit of a private key creates a unique time signature
Statistical analysis of thousands of transactions reveals patterns reports.zellic
Correlation analysis recovers the full private key

As Babylon Labs researchers demonstrated, execution times ScalarBaseMultNonConst range from 137 nanoseconds to 17.344 nanoseconds depending on the scalar length, creating a clear “time signature” for each secret value. reports.zellic

Real-World Threats and CVEs

Modern examples of critical vulnerabilities confirm the danger of timing attacks:

CVE-2024-48930 : Critical vulnerability in secp256k1 allowing private key recovery via 11 ECDH sessions security.snyk+1
CVE-2024-49364 : Private key extraction when signing a single malicious github+1 message
CVE-2024-49365 : Verification bypass in tiny-secp256k1 cvefeed

Minerva Attack: A Real-Life Demonstration

Research has shown that the Minerva attack can recover signature keys from signature samples of different messages with different nonces, using temporal information correlated with the nonce bit length. Even under the noisiest conditions, the attack requires only a few thousand samples to successfully recover the key. reports.zellic

Global Impact

In 2024, cryptocurrency hackers stole more than $2.2 billion, with private key compromises accounting for 43.8% of all thefts. The year’s largest attacks, including the $308 million DMM Bitcoin hack, highlight the critical importance of protecting against timing attacks. therecord+1

Critical vulnerability in Bitcoin implementation:

A Look Through the Prism of Timing Attacks on Cryptography

Privacy Breach: Temporal Side-Breaking Attacks Against Bitcoin Private Keys as a Global Threat to Cryptocurrency Security

This scientific title highlights the very essence of the threat—a critical vulnerability arising when implementing cryptographic operations with non-constant execution time, and the scale of the consequences of timing attacks for the Bitcoin ecosystem.

Research paper: The Impact of a Critical Timing Attack Vulnerability on the Bitcoin Ecosystem and Methods for Identifying It

Introduction

Digital currencies such as Bitcoin achieve their cryptographic security through the use of elliptic curve secp256k1 and strong electronic signature protocols (ECDSA). However, even mathematically strong cryptographic algorithms can be vulnerable if implemented incorrectly. One of the most dangerous and little-studied threats is the timing side-channel attack , which allows private keys to be extracted from legitimate software. papers.ssrn+2

The emergence of the vulnerability and the scientific name of the attack

A timing side-channel attack is an attack on the implementation of cryptographic operations in which an attacker analyzes the execution time of a function when processing secret data (nonce, private key). In Bitcoin software, a vulnerability arises if, for example, the function multiplying a point by a scalar ( ScalarBaseMultNonConst) executes faster or slower depending on the bit length of the scalar—that is, the value containing the cryptographic secret. arxiv+1

Scientific name of the attack:

Timing Side-Channel Attack ( usenix+2 )
Sometimes in literature – ECDSA Side-Channel Private Key Extraction Attack ( mbed-tls.readthedocs+1 )

If a library implements scalar multiplication of a point on a curve with variable execution time, an attacker can recover secret data with high accuracy by analyzing timing statistics. summerschool-croatia.ru+2

The Impact of the Attack on the Bitcoin Ecosystem

Compromising private keys . This attack allows one to recover the corresponding private key by observing the transaction execution time. As a result:
- Wallets can be completely hacked;
- User funds may be stolen immediately;
- Unauthorized (“double-spending”) transactions may occur. fox-it+2
A massive attack on wallets and nodes . The reliability of the entire Bitcoin ecosystem is at risk if a large portion of clients use a vulnerable implementation. summerschool-croatia.ru+1
Loss of reputation and trust . Critical vulnerabilities lead to a decline in trust in the network and a prolonged correction in the cryptocurrency market.

CVE identifier and examples

Such vulnerabilities are officially recorded in the Common Vulnerabilities and Exposures database:

CVE-2019-25003 – A vulnerability in libsecp256k1 allows for timing attacks on private keys. advisories.gitlab
CVE-2024-48930 – A critical vulnerability in the Node.js secp256k1 binding allows private key recovery via computation side effects. incibe+2
CVE-2019-18222 , CVE-2019-14318 – similar issues in other crypto libraries and ECDSA implementations. cvedetails+1

Scientific recommendations for prevention and correction

To stop the threat of time-based attacks:

Use only algorithms that implement operations on secret data strictly in constant time . cure53+2
Conduct independent scientific audits of open-source crypto libraries.
Immediately update software to patched versions or implement your own protective algorithms for masking, multiplicative encryption, and memory protection. cure53+1

Example of a safe implementation (Go):

go:

func Generator() *PublicKey {
    var (
        result JacobianPoint
        k      secp.ModNScalar
    )
    k.SetInt(1)
    ScalarBaseMult(&k, &result) // Функция гарантирует константное время!
    result.ToAffine()
    return NewPublicKey(&result.X, &result.Y)
}

Important: The replaced function must be independently verified to be free of temporary channels!

Conclusion

Timing side-channel attacks (TSCs) remain a critical threat to the security of cryptocurrency ecosystems, particularly Bitcoin. If successfully implemented, they could lead to massive private key compromises, financial losses, and system failures. Only continuous improvement of cryptographic libraries, rigorous scientific auditing, and the implementation of constant-time algorithms can ensure the safety of user funds and the future stability of the network. papers.ssrn+4

Cryptographic vulnerability

Analysis of cryptographic vulnerabilities in the presented btcec code

After a thorough examination of the presented code and an analysis of modern vulnerabilities in the secp256k1 cryptographic libraries, a critical timing attack vulnerability was discovered in the implementation of the Generator().

Identified vulnerability

Vulnerability line:

go:

ScalarBaseMultNonConst(&k, &result)

Description of the vulnerability

A function ScalarBaseMultNonConst in the btcd/dcrd library is vulnerable to timing attacks. This vulnerability allows attackers to recover private keys by analyzing the execution time of cryptographic operations. babylonlabs+1

Vulnerability mechanism

Variable execution time : ScalarBaseMultNonConst has a variable execution time that depends on the length of the scalar tlseminar.github+1
Information leakage through timing channels : The execution time of a function is approximately linear in ⌈lg(k)⌉, which creates a direct correlation between the computation time and the logarithm of the scalar k tlseminar.github
Attack on base multiplication : An attacker can use timing measurements to extract information about the nonce and subsequently recover the private key of babylonlabs

Technical details

Vulnerable process in Generator() function:

go:

func Generator() *PublicKey {
    var (
        result JacobianPoint
        k      secp.ModNScalar  // k устанавливается в 1
    )
    k.SetInt(1)
    ScalarBaseMultNonConst(&k, &result)  // ← УЯЗВИМОСТЬ ЗДЕСЬ
    result.ToAffine()
    return NewPublicKey(&result.X, &result.Y)
}

Attack through time channels

Research has shown that the ScalarBaseMultNonConst btcd implementation is susceptible to timing attacks that can compromise cryptographic operations: babylonlabs

Variable execution time : The function executes in time t(⌈lg(k)⌉-1), where t is the time to process one bit of the scalar tlseminar.github
Information leakage : An attacker can exploit the correlation between execution time and scalar to recover secret information

Related vulnerabilities in the ecosystem

This issue is not isolated—research has found multiple instances of timing attacks on secp256k1 implementations: wolfssl+1

CVE-2019-13628 : Nonce size leak in ECDSA signature operations in wolfSSL wolfssl
Babylon Labs Audit : Critical nonce reuse vulnerabilities found in babylonlabs adapter signatures
OpenSSL Timing Attacks : Documented attacks on the Montgomery Ladder implementation at tlseminar.github

Recommendations for elimination

1. Using constant time

Replace ScalarBaseMultNonConst with a constant-time implementation:

go:

// Безопасная альтернатива
ScalarBaseMult(&k, &result) // Константное время

2. Protection against time attacks

Implement additional protective measures:

Using cryptographically strong random number generators
Implementation of time channel masking
Validation of all input parameters

3. Updating libraries

Use updated versions of the secp256k1 libraries, which contain fixes for temporary vulnerabilities. github

Impact on safety

This vulnerability may result in:

Compromising private keys through timing analysis
Leakage of cryptographic secrets in transaction signing systems
Privacy violations in Bitcoin and other cryptocurrency systems

Although in this particular case the function Generator() uses a fixed value of k=1, using a vulnerable function ScalarBaseMultNonConst creates a potential attack vector and violates the principles of secure programming in cryptographic applications.

This research paper clearly explains why the use of functions with non-constant execution times in cryptographic operations poses a serious security threat to systems based on Bitcoin and other cryptocurrencies, requiring the immediate attention of developers and security researchers.

Timing Phantom Attack: Recovering Private Keys for Lost Bitcoin Wallets: A Critical Vulnerability with the "Time Morse" Technique and the Threat of a Timing Side Channel — **https://b8c.ru/btcninja**

BTCNinja: Exploitation of Timing Side-Channel Attacks for Private Key Recovery in Bitcoin

Timing side-channel vulnerabilities in Bitcoin’s cryptographic infrastructure pose a critical threat to the security and integrity of cryptocurrency wallets, enabling sophisticated extraction of private keys by analyzing subtle variations in cryptographic operation execution time. BTCNinja represents an advanced forensic exploitation toolkit crafted specifically to harness these weaknesses present in elliptic curve cryptography (secp256k1) implementations for the targeted recovery of lost or compromised Bitcoin wallet private keys.

The Role and Mechanism of BTCNinja

BTCNinja is purpose-built for monitoring and analyzing execution time discrepancies in Bitcoin cryptographic routines, such as scalar multiplication during ECDSA operations. Leveraging high-resolution timing probes, the tool collects and statistically analyzes thousands of samples from transaction signatures or wallet operations. By correlating these timing signatures with specific cryptographic secrets (private key bits or nonces), BTCNinja reconstructs the underlying private key using advanced correlation and regression techniques.

BTCNinja’s attack workflow consists of:

Passive timing measurement on targeted wallet operations (no malicious code injection required).
High-volume statistical analysis, revealing time signature patterns unique to each secret key.
Automated correlation and key recovery routines, reconstructing full private keys for bitcoin wallets lost or compromised.

Critical Timing Vulnerabilities Leveraged by BTCNinja

BTCNinja targets non-constant-time implementations, specifically functions like ScalarBaseMultNonConst in Go-based Bitcoin libraries (e.g. btcec, dcrd). The execution time of these functions varies linearly with the secret scalar’s bit length, providing a “Morse code of time” uniquely characterizing each private key. This direct correlation enables accurate key extraction when a vulnerable implementation is present.

Examples of exploited timing vulnerabilities:

Scalar multiplication with variable runtime, exposing the secret bit-length.
Nonce leakage in ECDSA signing, allowing signature-based key reconstruction.
Cross-session timing profile analysis, overcoming noise and environment variability.

Real-World Impact and Attack Scenarios

Implementation flaws in Bitcoin cryptography have led to the official registration of multiple CVEs for timing attacks, including CVE-2024-48930 and CVE-2019-25003. BTCNinja’s techniques are applicable to any affected wallet or node, enabling:

Theft or unauthorized recovery of lost wallet keys.
Large-scale compromise of funds in vulnerable Bitcoin clients.
Privacy violations through forensic reconstruction of user transactions.

In 2024 alone, billions in losses were attributed to private key attacks, with timing side-channel exploits recognized as a major contributor.

Countermeasures and Recommendations

The scientific literature and cryptographic best practices underline the necessity for constant-time cryptographic routines, the use of strong random masking, and regular security audits of wallet implementations. BTCNinja’s ability to exploit even small timing discrepancies emphasizes the urgency of these remediation measures.

Mitigation steps include:

Refactoring all scalar multiplication and cryptographic signing functions to constant-time implementations.
Integrating automatic timing anomaly detection into wallet software.
Employing masking and randomized input techniques during sensitive operations.

Conclusion

BTCNinja exemplifies the cutting-edge intersection of side-channel attack research and practical exploitation tools within the Bitcoin security landscape. Its approach demonstrates that even mathematically robust cryptographic primitives are susceptible to implementation-level vulnerabilities, capable of undermining the foundational security of cryptocurrency ecosystems. Timing attacks threaten not merely individual users, but the trust and financial stability of global digital assets. Only rigorous cryptographic engineering and proactive security practices can guard against the sophisticated forensic capabilities of tools like BTCNinja.

Current vulnerabilities in Secp256k1 implementations and effective methods for their elimination

Introduction

In recent years, elliptic curve cryptographic operations (Secp256k1) have become the foundation for the security of Bitcoin and many other blockchain applications. However, despite the high level of mathematical security of the curve itself, real-world implementations of dot multiplication operations (e.g., ScalarBaseMultNonConst) have proven vulnerable to timing attacks, which can lead to critical private key leaks and other security compromises. github+2

The mechanism of vulnerability occurrence

A timing attack is an attack on a cryptographic implementation in which an attacker analyzes the timing of an operation depending on the value of secret data (scalar, private key, nonce). In a number of popular Go libraries (e.g., btcec, dcrd), the function easychair+1

goScalarBaseMultNonConst(&k, &result)

Performs a multiplication using an algorithm whose execution time directly depends on the bit length of the scalar k. If the value k depends on a secret parameter, an attacker can perform a statistical analysis of the timing differences when processing different inputs, gradually obtaining information about the private key or nonce. go101+2

An example of an attack mechanism

The attacker initiates multiple operations with different input values and measures the execution time of each.
By means of correlation analysis, it is possible to reconstruct the value of a secret scalar based on a pre-known execution model.
Repeating the attack allows one to reconstruct the private key in a few thousand iterations and observations. cure53+1

Building a robust defense

Cryptographic rule

All operations on secret data (private key, nonce) must be performed strictly in constant time , regardless of the data values.

A reliable way to fix it

Instead of using the vulnerable function:

goScalarBaseMultNonConst(&k, &result)

it is necessary to use a constant-time implementation.

Safe code option

Example for Go implementation (btcec/dcrd):

go:

// Предположим, что библиотека содержит константно-временную реализацию ScalarBaseMult
ScalarBaseMult(&k, &result) // ЭТА ФУНКЦИЯ ГАРАНТИРУЕТ КОНСТАНТНОЕ ВРЕМЯ
result.ToAffine()
return NewPublicKey(&result.X, &result.Y)

If such a function is missing from the library version being used, it is recommended to either use a patch or implement an algorithm using double masking , memory encryption, and other classic methods of protection against side-channel attacks. github+1

Example of a camouflage pattern

go:

// Использование дополнительной случайной маски для скаляра
maskedK := k ^ randomMask
ScalarBaseMult(&maskedK, &result) // Выполнение точно в константное время
// После завершения операции маску удаляем

System-wide protection measures

Updating libraries : Always use the latest versions, which have gotten rid of variable runtimes. github
ECC Implementation Audit : Conduct regular independent audits of third-party cryptographic implementations.
Side-channel attack testing : Include automated tests that detect timing vulnerabilities. cure53

Conclusion

Timing attacks on dot multiplication operations on Secp256k1 are a real and extremely dangerous vector for compromising private keys. The security of such operations is achieved only through the use of constant-time algorithms and strict adherence to the implementation rules and updates of cryptographic libraries. Below is a fully secure code template to prevent this vulnerability: thib+2

go:

func Generator() *PublicKey {
    var (
        result JacobianPoint
        k      secp.ModNScalar
    )
    k.SetInt(1)
    ScalarBaseMult(&k, &result) // Безопасная операция!
    result.ToAffine()
    return NewPublicKey(&result.X, &result.Y)
}

The implementation of ScalarBaseMult must be constant-time! go101+2

Final conclusion for a scientific article

The critical timing side-channel attack vulnerability in Bitcoin’s cryptographic operations represents one of the most dangerous and difficult-to-detect vectors for compromising private keys. Unlike classic exploits, this attack does not require system penetration or malicious code injection—simply monitoring the execution time of standard cryptographic operations is sufficient to gradually recover sensitive data, including users’ private keys. bitvault+2

The particular danger of this type of vulnerability lies in its stealth: neither the user nor the system detects any signs of a threat until complete loss of control over funds. The attack undermines the fundamental integrity and confidentiality upon which the Bitcoin cryptoeconomy is built. Losing a private key due to a timing attack means not only direct theft of funds, but also an undermining of trust in the entire ecosystem, the threat of mass hacks, and adverse consequences for millions of users worldwide. wikipedia+2

Combating such attacks requires a deep scientific and engineering approach—constant-time implementations of critical algorithms, constant code auditing, implementation of transaction delays, and monitoring for suspicious anomalies in device and software performance. Temporal side-effect attacks are the main challenge facing modern cryptography today, and only systemic countermeasures can guarantee the security of funds, the integrity of private keys, and the sustainable development of digital currencies of the future. sciencedirect+2

Bitcoin must be secure not only mathematically, but also at the engineering level—otherwise, even the strongest cryptography becomes vulnerable to the insidiousness of side-channel attacks.

Literature and sources

[End-to-End Automated Cache-Timing Attack on OpenSSL ECDSA secp256k1] easychair
[GitHub: ScalarBaseMult non-constant time, fixes] github
[Thibaud Colas: Timing attacks everywhere] thib
[StackOverflow: Preventing timing attacks] stackoverflow
[Cure53 Audit: noble-secp256k1 Timing Attack Resistance] cure53

These measures provide robust protection against temporary attacks and guarantee the security of private key transactions, strengthening the fundamental security of cryptocurrency systems and wallets. cure53+1

Key terms: Timing Attack, ECDSA Side-Channel Attack, CVE-2019-25003, CVE-2024-48930, secp256k1, private key, Bitcoin Security, ScalarBaseMult constant time.

Literature:

Cryptanalysis