Iceberg Quantum Pinnacle Architecture Reduces RSA-2048 Breaking Requirement to Under 100,000 Physical Qubits

Iceberg Quantum (Sydney-based startup, $6M seed round) published the Pinnacle Architecture, a fault-tolerant quantum computing design using quantum LDPC codes instead of surface codes. Under standard hardware assumptions (physical error rate of 10⁻³, code cycle time of 1 µs, reaction time of 10 µs), the architecture factors RSA-2048 with fewer than 100,000 physical qubits - an order of magnitude below the previous best estimate of ~1 million (Gidney 2025).

How it works: The architecture uses three modular components: (1) Processing Units built from bridged QLDPC code blocks (specifically generalized bicycle codes) that encode 14 logical qubits in ~860 physical qubits at distance 16 - compared to 1 logical qubit in ~511 physical qubits for a surface code at the same distance; (2) Magic Engines that simultaneously produce and consume magic states for a continuous pipeline of T gates; and (3) Memory blocks for efficient qubit storage with parallel read access. A novel technique called Clifford frame cleaning enables flexible parallelism across processing units.

Key numbers for RSA-2048 factoring:
- Minimum qubits config: 97,000 physical qubits, ~1 month runtime
- Faster config: 151,000 physical qubits, ~1 week runtime
- Trapped ions: 3.1 million physical qubits, ~1 month runtime

Why This Matters for Crypto: Previous estimates assumed surface codes requiring ~1 million physical qubits for RSA-2048, placing CRQC capabilities beyond near-term hardware roadmaps. QLDPC codes compress this by 10x. Iceberg is already partnering with PsiQuantum (photonics), Diraq (spin qubits), and IonQ (trapped ions), all of which project systems of this scale within 3-5 years. While these results are based on simulations and theoretical resource estimates (not experimental demonstrations), they fundamentally reset the hardware threshold for cryptographically relevant quantum computing.

Important caveat: The paper does not address ECDSA/secp256k1 directly - the RSA result demonstrates the architecture's efficiency. Applying similar QLDPC-based architectures to elliptic curve cryptanalysis could yield comparable overhead reductions, potentially bringing the physical qubit requirement for Bitcoin key-breaking well below current 8 million estimates.