Vitalik Buterin, the co-founder of Ethereum, recently published an in-depth analysis on X urging the blockchain and cryptography community to adopt stronger security standards — specifically 128-bit security. According to him, the current security levels of many systems are becoming outdated as global computational power accelerates faster than ever.
Bitcoin reaches 2^96 hashes: What does this mean?
Buterin estimates that Bitcoin’s cumulative proof-of-work (PoW) — the total computational effort expended to mine the entire blockchain — has now reached roughly 2^96 hashes.
🔍 What is cumulative proof-of-work?
It measures the total mining work performed since Bitcoin’s genesis block.
It represents the “thickness” or total security weight of the Bitcoin chain.
To execute a 51% attack, an adversary would need to recreate this entire amount of work (or more), which is practically impossible.
Reaching 96-bit worth of cumulative PoW means that to brute-force or overwrite Bitcoin’s entire history, an attacker would have to surpass computational effort equivalent to 2^96 SHA-256 hashes — an astronomically large number far beyond the capabilities of any real-world computing system.
Why does Buterin want to move to 128-bit security?
Vitalik refers to Ethereum researcher Justin Drake, who has long pushed for cryptographic systems to target at least 128-bit security. Examples include:
BLS12-381 cryptographic curves
The Lean Ethereum roadmap
Modern signature schemes designed to resist quantum attacks
Why the 128-bit milestone matters:
• 96-bit security may soon be reachable
Global computational capacity is rising rapidly, especially with advancements in AI, GPUs, ASIC miners, and quantum computing.
• 128-bit security is considered safe for decades
128-bit security corresponds to 3.4 × 10^38 possibilities, an amount that no foreseeable computing technology can brute-force.
• Many legacy crypto systems barely reach 128-bit
Older signature schemes and hashing constructions may begin showing weaknesses as new technologies emerge.
• Standardizing stronger security keeps the entire ecosystem safe
A blockchain using outdated cryptographic primitives can become the weakest link and expose the broader ecosystem to risks.
Bitcoin is still secure — but this is a warning signal
Bitcoin’s SHA-256 and PoW remain extremely strong. However, hitting a cumulative security level equivalent to 96 bits signals that we are approaching thresholds where cryptographic systems must scale up.
Especially as:
Hash rates keep reaching new highs
ASIC hardware grows increasingly powerful
Quantum computing progresses rapidly
Newer blockchains use more complex cryptographic mechanisms
→ Without timely upgrades, older cryptographic systems could become critical points of vulnerability.
Conclusion: 128-bit security is essential for future-proofing blockchain
Buterin’s message is clear:
Bitcoin reaching 2^96 hashes is a major security milestone
But it also highlights how quickly global compute power is growing
The crypto industry must adopt 128-bit security or higher to remain safe over the long term
Vitalik warns that if the ecosystem does not strengthen its cryptographic foundations now, future risks will become far more severe.



