On September 8, 2026, IonQ (NYSE: IONQ) published the first full engineering blueprint for breaking secp256k1 — the elliptic curve Bitcoin uses to sign transactions. Not a simulation. An actual attack plan.
The numbers
19,397 physical qubits
1,457 logical qubits
~25.7 days per attempt
40.7% proven success probability (up to 63.3% under common heuristics, per IonQ)
No hardware exists yet that can run this. IonQ's own roadmap targets 10,000 fault-tolerant physical qubits by 2027 — about half of what this attack needs. They call it "a capability milestone first, a security finding second."
Why transparent wallets are exposed
The attack targets the public key. Transparent Bitcoin addresses expose that key the moment you spend — either it's already on-chain from a prior transaction, or it gets revealed the instant you broadcast a new one. That's the actual target for Shor's algorithm.
Why shielded wallets aren't
Z-TEXT runs on BitcoinZ and uses zk-SNARK shielded (z-address) transactions. The proof confirms a spend is valid without ever revealing the signing key — not at rest, not during spending. There's no exposure moment for this specific attack to exploit.
Important nuance: this isn't stronger math. The underlying curve is still classical and still theoretically breakable by a large enough quantum computer. The difference is opportunity, not cryptographic strength.
The message-layer story is different
Z-TEXT's key exchange runs on ML-KEM-768 (NIST FIPS 203), a genuinely post-quantum algorithm — automatically, on every handshake, since the 3.7.0 beta. This defends against harvest-now-decrypt-later: even captured ciphertext stays unreadable, because the exchange was never built on breakable math in the first place.
Signatures are still classical Ed25519. ML-DSA-65 isn't in use yet — worth being upfront about.
The one honest limit
The math hiding sender, receiver, and amount (ledger shielding itself) is still classical ECC — same family as HTTPS, online banking, VPNs. Breaking it needs ~2,500-4,000 error-corrected logical qubits. Real quantum hardware at that scale is 10-20 years out, per most researchers. That's an industry-wide limit, not a Z-TEXT-specific one.
Sources
IonQ blog post
IonQ investor press release
Interesting Engineering coverage
Full piece with more detail: https://z-text.org/quantum-attack-z-text-wallet-messages-2026/
Tags: #bitcoin #cryptography #quantumcomputing #privacy
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