Bitcoin
Ledger CTO on Cryptocurrency Security Challenges
CryptoSlate spoke with Ledger’s CTO Charles Guillemet at BTC Prague on a range of topics, from what actually happened during the Ledget connection kit explore the intricate challenges of securing such a high percentage of the world’s digital assets. Guillemet’s deep-rooted experience in cryptography and hardware security provides a solid foundation for his role at Ledger. He began his career designing secure integrated circuits, which later translated into his approach to creating secure elements for Ledger devices.
Security Challenges in Blockchain and Bitcoin
During the interview, Charles Guillemet delved into the distinct security challenges presented by blockchain technology and Bitcoin. His insights have been shaped by his extensive experience in secure integrated circuits and cryptography.
Guillemet explained that, in traditional bank cards and passports, security keys are managed by the bank or the State. However, in blockchain technology, individuals manage their own keys. This fundamental change introduces significant security challenges as users must ensure their valuables are protected from unauthorized access and loss. He highlighted:
“In accounting devices, you manage your keys while keeping your bank cards and your passport, this is the secret of your bank or state. This is the big difference.”
Since users own their value, it is imperative to protect it, ensuring that it is not lost or accessed by unauthorized parties. This requires robust measures to prevent access by software malware and to protect against physical attacks.
“Having a dedicated device is the best way to do this. And also you must prevent an attacker with physical access from gaining access to his secrets.”
The CTO also highlighted that the immutability of blockchain makes the security challenge even more significant. Ledger technology guarantees more than 20% of the market value, which is equivalent to approximately US$500 billion. This immense responsibility is managed by leveraging the best technology available to ensure safety. Guillemet confidently stated that, so far, his approach has been successful, allowing him to sleep well at night despite the high risks involved.
Ledger Response to Supply Chain Safety and Security Breaches
Charles Guillemet addressed Ledger’s approach to dealing with security breaches, particularly the incident involving Ledger Connection kit. He described the challenge posed by software supply chain attacks, emphasizing the difficulty in fully preventing such attacks.
When discussing the breach, Guillemet shared how a developer’s account was compromised via a phishing link, leading to an attacker obtaining the API key. This allowed the attacker to inject malicious code into the NPM repository used by websites integrating Ledger devices. He highlighted Ledger’s quick response to mitigate the impact:
“We realized the attack very quickly and were able to kill him very, very quickly. From the time he compromised access and we stopped the attack, only five hours had passed.”
Despite the breach, damage was limited due to Ledger’s immediate action and the security features inherent in its devices, which require users to manually sign transactions, ensuring transaction details are verified.
Guillemet further discussed the broader issue of supply chain security, emphasizing the complexity of managing software vulnerabilities. He highlighted that while due diligence and best practices can help, completely preventing supply chain attacks remains a significant challenge. He cited an example of a sophisticated supply chain attack:
“LG recently had a package in the UNIX distribution that was hacked by someone who compromised the open source repository by exploiting SSH servers. It spread to every server in the world before it was noticed.”
This example illustrated the widespread nature of supply chain attacks and the difficulty in detecting and mitigating them. Perhaps unsurprisingly, he advocated the use of hardware wallets for cryptographic security. However, he expertly explained why, clarifying that they offer a limited attack surface and can be audited thoroughly.
Human and technical security threats
Charles Guillemet provided a comprehensive overview of the multifaceted nature of security threats in the blockchain space, covering both human and technical elements. He emphasized that attackers are highly results-oriented, constantly evolving their strategies based on the cost and potential reward of their attacks. Initially, simple phishing attacks that tricked users into typing 24-word recovery phrases were prevalent. However, as users became more aware, attackers changed their tactics to more sophisticated methods.
Guillemet explained:
“Now, attackers are tricking users into signing complex transactions that they don’t understand, which leads to their wallets being depleted.”
He noted the rise of the organization cryptographic drain operations, where different parties collaborate to create and exploit crypto drains, sharing the proceeds at the smart contract level. Guillemet predicted that future attacks could focus on software wallets on phones, exploiting zero-day vulnerabilities that can provide full access to a device without user interaction.
Given the inherent vulnerabilities of mobile devices and Workspace devices, Guillemet emphasized the importance of recognizing that these devices are not secure by default. He recommended:
“If you think your data is protected on your desktop or laptop, think again. If there is an attacker determined to extract the data, nothing will stop them from doing so.”
He advised users to avoid storing sensitive information such as seeds or wallet files on their computers as they are prime targets for attackers.
Balancing security with usability is a significant challenge in the crypto wallet industry. Ledger’s approach prioritizes security as the North Star while continually striving to improve the user experience. Guillemet recognized that resources such as Ledger recovery, which aim to simplify the user experience, have generated debate. He explained that while these features are designed to help newcomers manage their 24-word recovery phrases more easily, they are completely optional:
“We are offering options, giving choice. It is an open platform. If you don’t like a feature, you don’t have to use it.”
The goal is to serve a wide range of users, from those who prefer complete control over their security to those who need easier-to-use solutions. Guillemet recognized that mass adoption of digital assets requires addressing usability problems without compromising security. Ledger aims to achieve this balance by offering flexible options while maintaining the highest security standards.