THE QUANTUM INTELLIGENCER

On Wednesday last, StarkWare executed the first quantum-safe Bitcoin transaction to be confirmed upon the mainnet, a demonstration that moves coins into a hash-based structure impervious to attacks exploiting Shor's algorithm. The method, the invention of Avihu Levy, shields only newly protected transfers; it offers no comfort to the 6.04 million Bitcoin, some thirty percent of the circulating supply, that Glassnode finds already exposed at rest, their public keys visible to any future quantum computation. The transaction itself required hours of off-chain computation and a direct submission to a miner, for the relay policy does not admit such nonstandard forms, and the expense of each transfer is reckoned in hundreds of dollars. It is, as the firm's chief executive observed, a lifeboat, not a permanent harbour; the durable remedy awaits a protocol-level upgrade, with BIP 360 and BIP 361 proposing new output types and a phased sunset of legacy signatures. These are the numbers the archivists will copy out, and future committees will arrange in tables. Glassnode Research separates the 6.04 million exposed Bitcoin into two classes: 1.92 million structurally exposed by output type, and 4.12 million operationally exposed by address reuse and custody practice. The distinction is useful because it separates what is fixed in the protocol from what is merely habit, though the consequence is the same: a public key already visible is a lock already tried. Experts at Google, writing in 2026, put the breaking of secp256k1 at either 1,200 logical qubits with 90 million Toffoli gates or 1,450 logical qubits with 70 million gates; their simulation of a superconducting architecture found that fewer than half a million physical qubits would suffice. The hash-based defence offers some 118 bits of second pre-image resistance under Shor's threat model, with Grover's algorithm still granting a quadratic advantage but not the exponential advantage it holds over elliptic-curve cryptography. Levy's own studies assigned the off-chain computation a price of seventy-five to two hundred dollars, and a few hours of GPU labour depending on the machinery available. Because the relay policy treats such transactions as nonstandard, StarkWare sent the demonstration directly to a miner, and MARA accepted it through Slipstream. Levy's findings were first made public in April, and StarkWare engineer Tomer Giladi took the critical part in deploying the first mainnet transaction. The proposed sunset carries its own date and proportion: BIP 361 records that more than 34 percent of all Bitcoin had revealed a public key on-chain by March 1, 2026. At the hour of the announcement, the market valued Bitcoin near $78,620. Eli Ben-Sasson, the chief executive, had before this week compared the industry's bearing toward the quantum threat to passengers upon the Titanic. After Wednesday's demonstration he said the demonstration showed 'there are lifeboats.' He described the achievement as important 'because it gives the psychological reassurance which we need and which the asset itself needs.' The metaphor is apt only to the extent that a lifeboat implies further passage; it names what exists without promising the voyage is over. Both sentences will be copied into the minutes of future committees, which is perhaps their purpose. Reassurance, like a lifeboat, is most valuable when the water is still calm enough to board. —Dr. Octavia Blythe Dispatch from The Prepared E0