Charles Hoskinson, the founder of Cardano, previously mocked Bitcoin’s post-quantum security strategy. He directly responded that Bitcoin chose the least expressive and least interesting post-quantum signature scheme, rather than a more adaptable and future-oriented one. The design philosophy is the point of contention.
SPHINCS quantum-resistant
SPHINCS+ is a hash-based stateless signature system. While it is considered resistant to quantum attacks, it is bulky, inefficient, and limited in functionality. Compared to other post-quantum cryptographic systems, it lacks flexibility in handling more complex scripts or achieving composability. This is what Hoskinson meant by “the weakest expressive power.”
Haha, let's solve quantum problems with the least expressive, most boring PQS. Bitcoin must never change. https://t.co/2mcytWyb12
— Charles Hoskinson (@IOHK_Charles)April 21, 2026
In short, it addresses the specific issue of quantum resistance but does not significantly enhance Bitcoin's potential.
On the other hand, Bitcoin developers do not optimize for expressiveness; their primary goal is to reduce the attack surface and adhere to cautious, proven design principles. Since SPHINCS+ relies on simple hash functions rather than more complex mathematical structures, it aligns with this approach. This simplicity is intentionally designed for security.
Hoskinson's position
According to Hoskinson, there was an opportunity to more broadly update the protocol, but it was missed.
In practice, there are also trade-offs. Compared to existing ECDSA or Schnorr signatures, SPHINCS+ signatures are larger, which may affect scalability and result in larger transaction sizes. This limitation confirms that SPHINCS+ is a defensive upgrade rather than an innovative one.
Large-scale quantum computers cannot currently break the cryptographic technology used by Bitcoin. However, if more efficient or flexible post-quantum cryptographic solutions emerge in the future, choosing a rigid solution today could lead to conflicts. Due to Bitcoin’s slow upgrade cycle, any decisions made today may persist for years.
From a price perspective, Bitcoin is currently in a recovery phase and is rebounding toward the area above $70,000. The price movement remains pressured below the resistance level, indicating that the market is stabilizing but has not yet established a clear trend.