Quantum Threat Grows as 35.4% of Bitcoin Supply Remains Exposed

Recent analytical data from Glassnode reveals a growing vulnerability within the Bitcoin network regarding future quantum computing attacks. As of November 2024, approximately 7.12 million BTC, representing 35.4% of the total circulating supply, has its public keys visible on the blockchain. This exposure provides a potential entry point for advanced cryptographic decryption, highlighting a critical security challenge for long-term digital asset preservation.

Drivers of Public Key Exposure

The visibility of these public keys is primarily attributed to specific network behaviors and legacy infrastructure. According to the report, the risk is distributed across several categories of holders:

• Address Reuse: Responsible for 25.8% of the exposed supply, occurring when users send multiple transactions from the same address.
• Exchange Wallets: Centralized trading platforms hold 11.6% of the vulnerable supply due to their operational structures.
• Legacy Protocols: Older transaction types that reveal the public key upon the first outgoing transfer.

While Bitcoin uses elliptic curve cryptography (ECDSA), which is currently secure, quantum computers could theoretically derive a private key if the public key is known. The data suggests a concerning trend, as the proportion of exposed keys has climbed steadily from 24.8% in early 2021 to its current level, indicating that many market participants are not prioritizing quantum-resistant hygiene.

Mitigating the Quantum Risk

Analysts emphasize that the threat is not immediate but requires proactive measures from the community. Glassnode points out that the risk is not inherent to the Bitcoin protocol itself but rather to how specific outputs are managed.

"Transferring these tokens to new, unexposed addresses can effectively eliminate this exposure risk."

By migrating funds to newly generated addresses (specifically those that have never sent a transaction), users can hide their public keys behind a double-hash layer. This process ensures that the public key remains unknown to the network—and potential attackers—until the moment the owner decides to spend the funds.

In conclusion, the rising percentage of exposed Bitcoin supply underscores a need for increased awareness regarding on-chain privacy and security. While the development of viable quantum computers capable of cracking secp256k1 remains a future prospect, the migration of the 7.12 million BTC to more secure address formats represents a vital step in safeguarding the network's long-term integrity against evolving technological threats.