Vitalik: Cryptographic Obfuscation Achieves Milestone Progress, But Practical Implementation Still Faces "Universe-Level" Performance Challenges

As disclosed in Vitalik Buterin's blog post (June 29, 2026), the most powerful primitive in the field of cryptography—indistinguishability obfuscation (iO)—has been theoretically achieved under reasonable security assumptions, but the current scheme's runtime still far exceeds the lifespan of the universe, leaving a huge gap to practical application. iO can transform any program into an "encrypted program", preserving input-output functionality while hiding internal logic, and is regarded as the ultimate cryptographic tool approaching a "trustless trusted third party". Combined with blockchain, it can theoretically enable high-value applications such as secure private voting systems without multi-party committees. The existing strictest schemes require nesting multiple layers of cryptographic primitives such as Fully Homomorphic Encryption (FHE), Attribute-Based Encryption (ABE), Functional Encryption (FE), and Randomized Encoding (XiO), superimposed with sub-exponential security parameter requirements, resulting in comprehensive overhead reaching the order of λ10λ10, making it practically inoperable. The article points out three future breakthrough paths: first, compressing the existing technology stack through algorithm optimization; second, building simpler schemes based on more aggressive lattice cryptography assumptions (such as diamond iO); third, exploring entirely new constructions that do not rely on lattices at all (such as local mixed obfuscation). The author believes that once any path succeeds, it will mean that the "problem is basically solved" in the field of cryptography.