Solana’s latest post-quantum security tests came with a steep trade-off. In trial runs conducted in April 2026, the network saw speed fall by nearly 90% after switching to quantum-resistant signatures, which were reported to be as much as 40 times larger than the cryptography currently in use.
Signature size quickly became a throughput problem
The test environment was built by Solana and Project Eleven to simulate future attack conditions by replacing Solana’s existing cryptography with post-quantum alternatives. According to Project Eleven CEO Alex Pruden, the much larger signatures immediately reduced the number of transactions the network could handle at the same time. The result was a sharp drop in throughput.
That matters because Solana’s architecture depends on high throughput and low latency. Heavier cryptographic data adds pressure across validation and storage, making execution harder under real network conditions. The security gain tested in theory came with a visible cost in performance.
Solana’s public-key model adds a separate risk
The trials also highlighted a structural issue beyond raw speed. The report says Solana exposes public keys directly, unlike Bitcoin and Ethereum. In a future quantum attack scenario, that design could leave wallets more exposed because an attacker would not need to wait before targeting them.
Pruden said a quantum system could immediately go after any wallet and then attempt to recover private keys without delay. That makes mitigation more urgent for Solana, since the exposure is tied to how the network works rather than only to transaction capacity.
Developers are testing interim defenses while full upgrades remain hard
A full network-wide migration is still difficult, so some developers are trying narrower fixes first. One of the approaches under review is Winternitz Vaults, designed to protect individual wallets without forcing an immediate protocol-level overhaul across the entire ecosystem.
Pruden also said the project has already launched a working testnet using quantum-resistant signatures. That puts Solana ahead of many blockchain ecosystems that are still discussing the issue at a high level. Even so, broader adoption is still limited. Any serious rollout would require coordinated changes across validators, developers, and users, and that remains a hard step.
At the same time, research from Google and academic teams has added urgency to the wider industry debate. Their findings suggest current encryption methods may be broken by quantum systems sooner than previously expected. For Solana, the latest tests turned that debate into a concrete engineering problem with measurable costs.