a16z Crypto upgrades Jolt zkVM: directly addressing the abuse of the "ZK" label and the lack of zero-knowledge privacy issues

In the crypto industry, ZK (Zero-Knowledge Proof) has almost become one of the most magical terms. From ZK-Rollups to zkEVM, it symbolizes both privacy and the future of scalability. However, on March 3, 2026, top venture capital firm Andreessen Horowitz's a16z Crypto dropped a "deep water bomb" in a blog post: openly criticizing the widespread misuse of the "ZK" label in the industry. They pointed out that most so-called zkVMs (Zero-Knowledge Virtual Machines) do not possess true zero-knowledge properties and merely leverage their "simplicity." Meanwhile, a16z announced the introduction of NovaBlindFold folding scheme into their open-source Jolt zkVM, enabling native support for zero-knowledge proofs. This is not just a technical iteration but a profound questioning of the industry's narrative.

Event Overview: An Upgrade and a Critique

On March 3, the a16z Crypto development team announced an important upgrade to Jolt zkVM. The core of this update is the introduction of the NovaBlindFold folding scheme, allowing Jolt to generate hidden proofs without revealing input data, thus natively supporting privacy-preserving applications.

What truly shook the industry was the sharp critique accompanying this technical update. a16z explicitly stated that the vast majority of zkVMs on the market are not truly "zero-knowledge." Their so-called "ZK" attribute often requires an additional costly "wrapping" process after proof generation—recursively verifying the original zkVM proof within another proof system that genuinely possesses zero-knowledge properties. This process is computationally expensive and often involves trusted setup, sacrificing transparency.

Source: a16z Crypto

a16z further pointed out that in the current developer context, "zk" has gradually become synonymous with "succinctness," meaning only that the proof size is small and verification is fast, completely neglecting the privacy core that "zero-knowledge" should represent.

From Privacy Original Intent to Scalability Tool to Conceptual Deformation

To understand the deeper meaning of this critique, we need to trace the evolution of ZK technology in blockchain:

• Emergence (mid-2010s): Represented by Zcash, ZK tech like zk-SNARKs was first widely adopted, with the primary goal of privacy—masking transaction data to enable confidential on-chain value transfer.
• Explosion (2020–2025): As Ethereum faced congestion, ZK tech was found to have another major value—scalability. ZK-Rollups became a star Layer 2 solution, processing many transactions off-chain and generating a "succinct" validity proof to submit to the main chain. During this phase, the focus shifted almost entirely to "succinctness" and "verifiability," with the privacy aspect of "zero-knowledge" being downplayed.
• Deformation (2025 onward): With the proliferation of ZK-Rollups, the term "ZK" began to be broadly used to refer to any project employing succinct proof tech, including various zkVMs. a16z's critique is a concentrated critique of this conceptual deformation.

The Technical Logic and Ledger Behind the Jolt Upgrade

This upgrade of Jolt zkVM essentially performs a precise surgical correction of the above "deformation" issue. Instead of adopting expensive, trust-dependent "wrapping" processes, the Jolt team turned to a scheme dating back to the 1990s—NovaBlindFold.

Data-wise, this upgrade offers an extremely cost-effective solution. Using NovaBlindFold, Jolt produces truly privacy-preserving zero-knowledge proofs, with the only cost being an increase of about 3 KB in proof size. For blockchain systems that handle massive data, this is negligible.

This structural improvement means developers can finally have a ready-to-use, native privacy-supporting zkVM environment without sacrificing performance. It paves the way for building truly privacy-preserving applications like privacy DeFi, anonymous voting, and identity verification.

Industry Controversy and Diverging Paths

a16z's statement quickly sparked clear debate within the industry.

• Mainstream media and some developers: Generally agree with a16z. Outlets like The Block directly quoted the blog post, recognizing the long-standing terminology abuse. Many technically-minded observers see this as an important correction, helping the industry return to its technical roots, especially as privacy narratives regain prominence.
• Projects labeled "ZK" but only implementing "succinctness": For projects that have long used the "ZK" label but only achieve succinct proofs, a16z's critique is a sharp challenge. They might argue that in the context of scalability, "ZK" has become a shorthand for "ZK-Rollup," an industry convention rather than an intentional misrepresentation. The core dispute revolves around whether "succinctness" or "privacy" should be the primary meaning of "ZK."
• Investment perspective: As Digital Currency Group CEO Barry Silbert recently stated, privacy will be a key focus for the next wave of capital inflows. a16z's move is not just a technical stance but also a strategic market positioning, preemptively capturing the privacy computing trend.

Why Must the "ZK" Label Be Reexamined?

A simple logical deduction: if a system widely called "zkVM" does not actually protect privacy, what happens when developers build applications on it? Suppose a developer wants to create a decentralized credit scoring app. Users need to prove their credit score exceeds 700 without revealing sensitive details like specific scores or transaction history. If they use a "pseudo ZK" zkVM, the proof might only demonstrate that a computation was correct, but the user's credit data could be exposed in the input or state, or reconstructed via side-channel attacks. The final application would offer no real privacy guarantees.

Therefore, a16z's scrutiny is not just wordplay. As demand for privacy protection grows—especially with institutional capital requiring data privacy—precise definitions of "ZK" have shifted from academic discussion to product compliance and commercial deployment. The reality is that most existing zkVMs cannot meet true privacy application needs; the consensus is that this situation hampers industry development. With native ZK solutions like Jolt maturing, the market will likely begin to distinguish clearly between "succinct proofs" and "zero-knowledge proofs," with projects relying solely on superficial "ZK" labels facing valuation resets.

A Rebalancing of the Value from "Scalability" Back to "Privacy"

This event impacts the industry on multiple levels:

• Standard reshaping: As a16z, a major investor and developer force, open-sourcing and upgrading Jolt provides a high-performance "native ZK" benchmark. This may prompt other zkVM projects to revisit their architectures, prioritizing genuine privacy support as a core metric.
• Acceleration of privacy track: When "succinctness" no longer substitutes for "privacy," market demand for privacy applications will surge. Jolt's upgrade signals readiness for privacy-focused dApps, such as privacy DeFi, DID, and compliant solutions.
• Bursting the concept bubble: Just as "blockchain" was once overused, "ZK" is now under scrutiny. a16z's public critique helps prune projects that rely on superficial "ZK" branding without real privacy tech, guiding capital and attention toward genuinely capable teams. This is a healthy reshuffle for industry long-term health.

Evolutionary Scenarios

Based on the above, several future industry scenarios can be envisioned:

• Scenario 1: Tiered Standards

The market will develop a layered understanding of ZK tech, with precise terms like "ZK (Privacy)," "ZK (Succinct)," or "Validity Proof." Projects will be more cautious in marketing to avoid misleading investors and users. Performance metrics will include both proof size and privacy guarantees.

• Scenario 2: Privacy Application Boom

Starting from Jolt's upgrade and combined with Layer 2 projects like ZKsync emphasizing "default privacy" in their 2026 roadmaps, we may see a wave of privacy DeFi, privacy DID, and compliant applications in the next 1-2 years. Privacy will become the next major narrative after Restaking.

• Scenario 3: Regulatory and Compliance Push

As global data privacy laws (like GDPR) tighten, blockchain transparency may become a barrier for institutional adoption. Native zero-knowledge proof tech can meet regulatory "data minimization" principles while providing verifiable trust. This could push more projects to abandon "pseudo ZK" and adopt genuine privacy solutions.

Conclusion

a16z Crypto's update to Jolt zkVM is more than a routine upgrade. It reflects a mirror, revealing the industry's conceptual confusion and restlessness amid rapid growth. When "ZK" is reduced to a marketing prefix, the cryptographic mission—privacy protection—risks being forgotten. The introduction of NovaBlindFold not only makes Jolt one of the few truly "authentic" zkVMs but also ignites a public discussion on the authenticity of technical narratives.

For the entire industry, this may be a memorable moment: when bubbles burst, only respect for the core technology and a return to fundamentals can build a solid bridge to large-scale adoption. Just as Jolt's upgrade adds only about 3 KB overhead, the cost of shifting toward genuine "zero-knowledge" may be smaller than we think, and the reward will be a more trustworthy, private Web3 future.