CLASSIFIED BRIEFING

QUANTUM THREAT
ASSESSMENT

Google Quantum AI — March 30, 2026

How close is a quantum computer to breaking your Bitcoin wallet?

Coin Bureau Podcast x The Better Traders

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The Paper

WHAT GOOGLE JUST PUBLISHED

"Securing Elliptic Curve Cryptocurrencies against Quantum Vulnerabilities"
Ryan Babbush • Craig Gidney • Hartmut Neven + 6 others
Google Quantum AI • UC Berkeley • Ethereum Foundation • Stanford
Published March 30, 2026
Notable: Google used a zero-knowledge proof to verify findings without releasing attack instructions. The math is real. The threat is quantified. The timeline just got shorter.
"The expected emergence of cryptographically relevant quantum computers will represent a singular discontinuity in the history of digital security."
— Babbush et al., Google Quantum AI, 2026
BITCOIN
ETHEREUM
ALL ECDLP BLOCKCHAINS
The Math

THE LOCK ON EVERY CRYPTO WALLET

x y P Q = nP secp256k1: y² = x³ + 7
Private key n: secret
Public key Q=nP: visible
Reverse: ECDLP
Every Bitcoin wallet uses this math. Your private key generates a public key through a one-way operation on this curve.
Reversing this — finding n from Q — would take a classical computer longer than the age of the universe.
It's been unbreakable for 30 years. Until now.
Used by:
BITCOIN ETHEREUM SOLANA CARDANO AVALANCHE
Quantum Advantage

WHY QUANTUM CHANGES EVERYTHING

Shor's Algorithm solves ECDLP exponentially faster
CLASSICAL COMPUTER
age of universe
1030 years to crack secp256k1
Classical computers test one possibility at a time. The keyspace has more combinations than atoms in the observable universe.
VS
QUANTUM (SHOR'S ALGORITHM)
MINUTES
~Minutes to crack secp256k1
How Shor's Algorithm works: 1. Superposition tests all answers simultaneously

2. Quantum Fourier Transform extracts the period

3. Reduces ECDLP to polynomial time
2022 ESTIMATE — Google
~0
Physical Qubits Required
Physical qubits are the raw hardware building blocks. Logical qubits are error-corrected qubits — it takes thousands of physical qubits to make one reliable logical qubit.
This was already an alarming number in 2022
2026 ESTIMATE — Google Willow Architecture
<0
Physical Qubits Required
20x REDUCTION
Based on Google Willow processor architecture. The bar just dropped dramatically — and it's still falling.
The Reduction Visualized

THE QUBIT REQUIREMENT FELL 20x

0 2M 5M 8M 10M 2022 ~10,000,000 qubits ~10 MILLION 2026 <500,000 qubits <500K
Execution time: MINUTES on superconducting hardware
Context: No CRQC exists today. This is a resource estimate. The bar is lower than we thought, and it's falling.
Circuit Design

TWO ATTACK CIRCUIT CONFIGURATIONS

Circuit Configuration A
High-Depth / Low-Width
Logical Qubits~1,200
Toffoli Gates90M
StrategyDepth-optimized
Uses fewer qubits but runs a deeper circuit. Trades qubit count for more sequential operations.
Circuit Configuration B
Low-Depth / High-Width
Logical Qubits~1,450
Toffoli Gates70M
StrategyWidth-optimized
Uses more qubits to run a shallower circuit. Faster execution, higher hardware demand.
What this means: Both configurations use dramatically fewer resources than 2022 estimates. Either configuration could theoretically execute a full Bitcoin key attack once a CRQC with sufficient physical qubits exists.
Attack Vectors

GOOGLE IDENTIFIED TWO DISTINCT ATTACKS

TX BROADCAST Public key visible MEMPOOL WAIT ~10 minutes CONFIRMED Block mined ▲ ON-SPEND ATTACK WINDOW ▲
ON-SPEND ATTACK
Target transactions while in the mempool. Public key is briefly exposed. CRQC has ~10 minutes to crack and replace.
CRITICAL
AT-REST ATTACK
Target old wallets with permanently exposed public keys. No time pressure — attack can happen anytime.
HIGH
Attack Vector 1

ON-SPEND ATTACK — DEEP DIVE

User broadcasts TX Public key visible in mempool 10-minute window starts CRQC cracks private key quantum attack runs Fraudulent TX submitted Race to confirmation
Hardware
SUPERCONDUCTING
PHOTONIC • SILICON
Attack Window
~10 min
Threat Level
CRITICAL
Mitigation
Private mempools, commit-reveal schemes
Attack Vector 2

AT-REST ATTACK — DEEP DIVE

Old P2PK Address Public key permanently on-chain PERMANENTLY EXPOSED ON-CHAIN CRQC attacks anytime Funds stolen — no time limit no timer
Hardware
NEUTRAL ATOM
ION TRAP
Time Needed
Hours to days
Threat Level
HIGH
At-Risk Addresses
~4M Bitcoin addresses with permanently exposed public keys
Risk Assessment

WHO IS AT RISK? (1/2)

ChainSignature SchemeQuantum RiskNotes
Bitcoin — exposed P2PKsecp256k1 ECDSAHIGH~4M addresses permanently exposed
Bitcoin — new transactionssecp256k1 ECDSAMEDIUMProtected behind hash until spend
Ethereum (ETH)secp256k1 ECDSACRITICALAccount model = permanent public key
Solana (SOL)Ed25519HIGHDifferent curve, still ECDLP-based
ETH Smart ContractsVariousCRITICALAdmin keys reused; quantum enables classical exploits
Risk Assessment

WHO IS AT RISK? (2/2)

ChainSignature SchemeQuantum RiskNotes
ETH Proof-of-StakeBLS SignaturesHIGHConsensus layer vulnerable
ETH DASKZG CommitmentsHIGHData availability layer exposed
Zcash (ZEC) — shieldedECDLP-freeSAFEQuantum resistant
Bitcoin PoWSHA-256SAFEGrover's offers minimal speedup
AlgorandPQC migrationMEDIUMActively migrating to PQC
95%+ of all crypto uses ECDLP-based signatures
The Dormant Asset Problem
~0 BTC
Estimated coins with permanently exposed public keys
Includes Satoshi's ~1.1M coins in early P2PK addresses — fully vulnerable to at-rest quantum attack.
At ~$100K/BTC, that's approximately $110 billion at risk
The Hard Problem

THERE IS NO CLEAN ANSWER

DO NOTHING

A CRQC operator drains all dormant wallets. Billions stolen instantly. Market chaos. The Bitcoin trust model collapses. "Hard money" becomes "stolen money."

FORCE DESTRUCTION

Protocol-level burning of exposed coins. "Your coins are safe forever" becomes a lie. Breaks Bitcoin's trust model from the other direction. Sets precedent for confiscation.

"The challenge posed by dormant assets illustrates why policy engagement must accompany technical solutions."
Policy Options

THE 6 OPTIONS ON THE TABLE

01
Do Nothing
Let quantum attackers take dormant coins. Maximum ideological purity, maximum financial damage.
DANGEROUS
02
Burn
Protocol-level destruction of vulnerable coins after a migration deadline. Irreversible.
COMPLEX
03
Hourglass
Freeze (not burn) vulnerable coins. Owners can reclaim by proving ownership with a quantum-safe signature.
VIABLE
04
Bad Sidechain
Migrate to a quantum-safe sidechain. Paper argues this creates dangerous fragmentation.
DANGEROUS
05
Digital Salvage
Regulated government recovery of exposed coins. Paper explores legal and technical frameworks.
COMPLEX
06
National Security Response
State-level intervention to secure or redistribute vulnerable assets before adversaries exploit them.
COMPLEX
Action Items

WHAT INDIVIDUALS SHOULD DO NOW

Stop reusing wallet addresses — use a fresh address every transaction
Move funds out of old P2PK and reused P2PKH addresses now
Use Taproot (P2TR) addresses — never expose the public key before spending
Watch your blockchain's PQC migration timeline — be ready to move
Protocol Action

WHAT BLOCKCHAINS MUST DO

Deadline: Before 2030
Migrate to CRYSTALS-Dilithium or FALCON
Both are NIST-approved post-quantum cryptography standards
Deploy private mempools
Prevents on-spend attack by hiding transactions until confirmation
Implement commit-reveal transaction schemes
Hides public key until after the transaction is committed
Plan for dormant coin policy — start community discussion now
There is no good option. But "no plan" is the worst option.
The Timeline

THE WINDOW IS CLOSING

2016 Google starts internal PQC rollout 2026 ▶ YOU ARE HERE Google paper published <500K qubits 2029 Industry PQC deadline target 203X CRQC possible Timeline unknown
The quantum threat is not here yet.  The preparation window is now.
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The Better Traders
Source
Babbush et al. (2026)
"Securing Elliptic Curve Cryptocurrencies against Quantum Vulnerabilities"
Google Quantum AI • UC Berkeley • Ethereum Foundation • Stanford
Published March 30, 2026
For educational purposes only. Not financial advice.
QUANTUM THREAT ASSESSMENT
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