The cryptocurrency that replaced Bitcoin's vulnerable cryptography before quantum computers arrived.
NIST's draft transition guidance (IR 8547, 2024) targets deprecation of classical cryptography by 2030 and disallowance by 2035. The Federal Reserve's 2025 analysis warns that blockchain data is uniquely vulnerable to "Harvest Now, Decrypt Later" attacks — adversaries record today's public transactions and derive private keys once quantum computers arrive [FEDS 2025-093].
For Bitcoin: millions of BTC remain in quantum-vulnerable address formats, including coins in P2PK addresses with no possibility of migration.1
Estimates range from ~5.9M to ~6.9M BTC depending on methodology and address classification. See Deloitte (2019), FEDS 2025-093, and Google Quantum AI analysis. ↩
Every transaction since December 27, 2020 is signed with Falcon-512 — a post-quantum signature scheme selected by NIST for standardization. There is nothing to migrate because quantum resistance was built in from block zero.
Tidecoin adopted PQ cryptography 10 years ahead of schedule.
Tidecoin replaces Bitcoin's ECDSA with FALCON-512, a lattice-based digital signature scheme selected by NIST for standardization as FN-DSA (Draft FIPS 206). Every transaction since genesis (December 27, 2020) is signed with post-quantum cryptography — no migration needed. Built on Bitcoin Core v30. ~21 million TDC max supply. CPU-mineable. Zero publicly disclosed security incidents.
Lattice-based digital signatures selected by NIST for standardization as FN-DSA (Draft FIPS 206). 666-byte signatures with constant-time integer emulation — no floating-point side channels. Among the most compact NIST-track lattice signature options for blockchain use.
Falcon-512/1024 (Draft FIPS 206) + ML-DSA-44/65/87 (FIPS 204, finalized). All implemented and tested. Multi-scheme agility means if one algorithm is compromised, alternatives activate via consensus upgrade.
ML-KEM-512 (NIST FIPS 203) replaces Bitcoin's ECDH-based key exchange. Every node-to-node connection uses post-quantum encrypted transport, enabled by default.
Post-Quantum Hierarchical Deterministic wallet replaces BIP-32. Hardened-only derivation with SHA-512 KDF. Multi-seed, multi-scheme, encrypted storage.
YespowerTIDE memory-hard algorithm (N=2048, r=8). Designed for broad CPU participation. Fair distribution.
Not a new chain — 15+ years of battle-tested Bitcoin consensus logic. UTXO model, scripting system, peer-to-peer network, with cryptographic components replaced or extended where quantum security requires it.
| Feature | Tidecoin | QRL | Bitcoin (BIP-360) | Algorand |
|---|---|---|---|---|
| PQ since genesis | Yes (Dec 2020) | Yes (Jun 2018) | No (proposal stage) | No (Nov 2025) |
| Signature scheme | FALCON-512 (NIST Draft FIPS 206) | XMSS (stateful, hash-based) | Proposes ML-DSA | Falcon-1024 |
| Stateless signatures | Yes (unlimited signing) | No (limited key reuse) | Proposed | Yes |
| Signature size | 666 bytes | ~2,500 bytes | N/A | 1,280 bytes |
| PQ P2P transport | ML-KEM-512 (FIPS 203) | No | No | No |
| PQ HD wallet | PQHD (custom) | No | Proposed | No |
| Number of PQ schemes | 5 (NIST standard) | 1 | Proposed | 1 |
| Bitcoin codebase | Yes (Core v30) | Independent | Is Bitcoin | Independent |
| Consensus | PoW (CPU + merged mining) | PoW → PoS | PoW (SHA-256d) | Pure PoS |
| Max supply | ~21M TDC | 65M QRL | ~21M BTC | 10B ALGO |
Sources: QRL documentation (theqrl.org), BIP-360 specification (bip360.org), Algorand Foundation, NIST FIPS 203/204/206.
The quantum threat to cryptocurrency is just entering mainstream awareness. Tidecoin has been ready since 2020.
Tidecoin launched with PQ cryptography ≈3.6 years before NIST finalized its standards.
NIST's post-quantum standards (FIPS 203, 204) were finalized in August 2024. FN-DSA (Draft FIPS 206, covering FALCON) remains in draft. The Federal Reserve's "Harvest Now, Decrypt Later" analysis was published in 2025. Federal agencies have until 2035 to complete migration. Tidecoin's post-quantum signatures have been live since December 27, 2020 — years before any of these milestones.
