Opinion by: Vikash Singh, Principal Investor at Stillmark

The Bybit hack resulted in the largest loss of funds to cyber hackers by a cryptocurrency exchange in history. It served as a wake-up call for those complacent about the state of security threats in the digital assets space. Everyone must learn the lesson from this heist — enterprise-grade custody solutions require tech to be accompanied by transparency.

Unlike many previous incidents, this loss of funds was not due to a faulty smart contract, lost/mismanaged keys or deliberate mismanagement or rehypothecation of user funds, but rather a sophisticated social engineering attack that exploited vulnerabilities in operational security. 

This hack differs from earlier eras because it happened to a major global exchange that takes security and compliance seriously. It’s a reminder that, in crypto, there’s no such thing as “good enough” security.

The anatomy of a heist 

A technical overview of the Bybit attack is key for understanding how companies can proactively strengthen their security against such attacks. Initially, a developer machine belonging to Safe, an asset management platform offering multisig Ethereum wallets used by Bybit, was compromised. This initial breach granted the attackers unauthorized access to Safe’s Amazon Web Services (AWS) environment, including its S3 storage bucket. 

The attackers then pushed a malicious JavaScript file into this bucket, which was subsequently distributed to users via access to the Safe UI. The JS code manipulated the transaction content displayed to the user during the signing process, effectively tricking them into authorizing transfers to the attackers’ wallets while believing they were confirming legitimate transactions. 

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This highlights how even highly robust security at the technical level, like multisig, can be vulnerable if not implemented correctly. They can lull users into a false sense of security that can be fatal.

Layered security

While multisignature security setups have long been considered the gold standard in digital asset security, the Bybit hack underscores the need for further analysis and transparency on the implementation of these systems, including the layers of security that exist to mitigate attacks that exploit operational security and the human layer in addition to verification of the smart contracts themselves. 

A robust security framework for safeguarding digital assets should prioritize multi-layered verification and restrict the scope of potential interactions. Such a framework demonstrably enhances protection against attacks.

A well-designed system implements a thorough verification process for all transactions. For example, a triple-check verification system involves the mobile application verifying the server’s data, the server checking the mobile application’s data, and the hardware wallet verifying the server’s data. If any of these checks fail, the transaction will not be signed. This multi-layered approach contrasts with systems that directly interface with onchain contracts, potentially lacking critical server-side checks. These checks are essential for fault tolerance, especially if the user’s interface is compromised.

A secure framework should limit the scope of possible interactions with digital asset vaults. Restricting actions to a minimal set, like sending, receiving and managing signers, reduces potential attack vectors associated with complex smart contract modifications.

Using a dedicated mobile application for sensitive operations, like transaction creation and display, adds another security layer. Mobile platforms often offer better resistance to compromise and spoofing compared to browser-based wallets or multisig interfaces. This reliance on a dedicated application enhances the overall security posture.

Transparency upgrades

To bolster transparency, businesses can leverage the capabilities of proof-of-reserve software. These can defend multisignature custody setups from UI-targeted attacks by providing an independent, self-auditable view of chain state/ownership and verifying that the correct set of keys is available to spend funds in a given address/contract (akin to a health check). 

As institutional adoption of Bitcoin (BTC) and digital assets continues, custody providers must transparently communicate such details on the security models of their systems in addition to the design decisions behind them: This is the true “gold standard” of crypto security. 

Transparency should extend to how the nature of the underlying protocols alters the attack surface of custody setups, including multisignature wallets. Bitcoin has prioritized human-verifiable transfers where signers confirm destination addresses directly rather than confirm engagement in complex smart contracts, which require additional steps/dependencies to reveal the flow of funds. 

In the case of the Bybit hack, this would enable the human signer to detect more easily that the address shown by the hardware wallet did not match the spoofed UI.

While expressive smart contracts expand the application design space, they increase the attack surface and make formal security audits more challenging. Bitcoin’s well-established multisignature standards, including a native multisig opcode, create additional security barriers against such attacks. The Bitcoin protocol has historically favored simplicity in its design, which reduces the attack surface not just at the smart contracting layer but also at the UX/human layer, including hardware wallet users. 

Increasing regulatory acceptance shows how far Bitcoin has come since its early era of widespread hacks and frauds, but Bybit shows we must never let our guard slip. Bitcoin represents financial freedom — and the price of liberty is eternal vigilance.

Opinion by: Vikash Singh, Principal Investor at Stillmark.

This article is for general information purposes and is not intended to be and should not be taken as legal or investment advice. The views, thoughts, and opinions expressed here are the author’s alone and do not necessarily reflect or represent the views and opinions of Cointelegraph.