According to Kohaku project manager at the Ethereum Foundation, Nicolas Consigny, Ethereum can start adding post-quantum security to accounts for as little as $0.07, without waiting for a strenuous fork.
On Saturday postConsigny shared paper proposing a cheaper way for Ethereum users to protect their accounts from future quantum computing threats. This approach adapts SPHINCS+, a post-quantum signature standard developed by the US National Institute of Standards and Technology, to work more efficiently on Ethereum.
The proposal, dubbed “SPHINCS-”, aims to reduce on-chain verification costs without requiring protocol changes or precompilation. Consigny has identified SPHINCS as a bridge towards a future post-quantum signature system called “leanSPHINCS” that aims to further reduce verification costs through aggregation.
The proposal aims to address the long-term quantum threat risk to Ethereum’s elliptic curve digital signature algorithm with a cost-effective solution that can be implemented before a dedicated strenuous fork is developed.
A variant of the SPHINC signature scheme, security degradation and onchain verification costs. Source: Ethresearch.ch
Related: Adam Back claims that Bitcoin’s post-quantum change could reveal Satoshi’s real stash
The future threats of quantum computing have the crypto community buzzing
In April, post-quantum startup Project Eleven awarded an award to researcher Giancarlo Lelli for using a quantum computer to crack a 15-bit elliptic curve key.
Bitcoin keys are 256 bits long, which is much larger than the 15-bit key that Lelli managed to crack. He derived the private key from the public key paired with it, using a variant of Shor’s algorithm, a quantum computing technique that theoretically poses a threat to the type of cryptography used by Bitcoin.
According to Glassnode, approximately 1.92 million Bitcoins, representing almost 10% of the total supply, are considered “structurally unsafe” in a future quantum attack scenario. Another 4.12 million BTC, or 20.6% of the supply, was classified as “operationally insecure” due to key or address management practices.

Source: Glass knot
The analytics firm estimates that the remaining 69.8% of the supply, or 13.99 million Bitcoins, remains unaffected by quantum computing, which is broadly in line with Ark Invest’s March estimate that 65% of the supply was secure.
Warehouse: Bitcoin and the Quantum Computer Threat – Timeline and Solutions (2025–2035)
