Design Positioning

Post-quantum blockchain designs differ in what they protect and when they protect it. Some retrofit post-quantum signatures onto an existing classical chain. Some use stateful hash-based signatures. Some only swap the transaction signature algorithm. Tidecoin’s position is different: it is a Bitcoin-architecture chain that started with post-quantum transaction signatures and extends the PQ design into wallet derivation, script hashing, transport encryption, and the long-term mining plan.

This page explains those design tradeoffs. It is not a claims page and not a ranking of other projects. For exact protocol rules, use Consensus Rules and the child protocol pages.

Approach comparison

Approach	What it does well	Main tradeoff
Classical-chain retrofit	Preserves an existing network and asset history.	Requires social coordination, migration transactions, block space, and decisions about unmigrated funds.
Signature-only PQ swap	Replaces the most obvious Shor-vulnerable primitive.	Leaves wallet derivation, transport, script-hash margin, and migration UX as separate problems.
Stateful hash-based signatures	Uses conservative hash-based assumptions.	Requires signer state management; key reuse and backup/restore mistakes can become severe.
Full-stack PQ from genesis	Avoids classical-signature migration debt and can design wallets/protocols around PQ constraints.	Starts with a smaller network and must earn liquidity, tooling, and mining adoption.

Tidecoin is in the full-stack PQ-from-genesis category.

Tidecoin’s design choices

Layer	Tidecoin choice	Reason
Transaction signatures	Falcon-512 from genesis; Falcon-1024 and ML-DSA built for agility	Avoid ECDSA/Schnorr exposure and allow future scheme diversity.
Wallet derivation	PQHD hardened-only derivation	Avoid BIP32/xpub assumptions that depend on elliptic-curve public derivation.
Script hashing	Witness v1 P2WSH-512 after AuxPoW	Provide a higher-margin SHA-512 script-hash path.
P2P transport	ML-KEM-512 v2 transport	Avoid quantum-vulnerable ECDH in encrypted relay transport.
Proof-of-work lifecycle	YespowerTIDE launch phase, scrypt AuxPoW path	Combine accessible initial distribution with a long-term merged-mining security path.
Codebase base	Bitcoin Core-derived UTXO architecture	Keep the proven UTXO, validation, networking, mempool, wallet, and test architecture where possible.

Why not only retrofit

A retrofit can be the right path for a chain that already has large economic weight, but it inherits migration problems:

Existing funds may be held by lost keys or inactive users.
Old public keys already exposed on chain remain exposed forever.
Migration consumes block space and may take years.
Wallets, exchanges, custody systems, and hardware devices must all coordinate support.
Governance must decide what to do about coins that never migrate.

Tidecoin avoids that specific migration problem by using post-quantum signatures from genesis. It does not avoid the harder ecosystem problem: users, miners, exchanges, and developers still need high-quality tooling and documentation.

Why not stateful signatures

Stateful hash-based signatures such as XMSS or LMS have conservative security assumptions, but they require careful signer state. Reusing a one-time signing state can weaken or destroy security. That is a poor fit for many cryptocurrency workflows:

Workflow	Stateful-signature concern
Wallet backup and restore	Restoring an old backup can roll back signer state.
Multidevice wallets	Devices must coordinate signing state exactly.
Hot wallets and exchanges	Operational mistakes can reuse state at scale.
Offline signing	State transfer between online and offline systems becomes part of the safety model.

Tidecoin chose stateless lattice signatures so normal wallet usage does not depend on a per-key signature counter or one-time signature budget.

Why full-stack PQ matters

Replacing ECDSA is necessary, but it is not the whole PQ design problem. A useful cryptocurrency stack also has:

Area	PQ-relevant question
Wallets	Can keys be derived without unsafe public derivation?
Scripts	Is there a high-margin script-hash path?
Transport	Can peer encryption survive future quantum key recovery?
Mining	Does long-term PoW security depend on a small standalone hash market?
Integrations	Can exchanges, explorers, wallets, and pools reason about activation and byte formats without guessing?

Tidecoin’s docs and protocol pages should make those boundaries explicit instead of presenting “post-quantum” as a single feature.

Current positioning

Tidecoin is best described as:

A Bitcoin Core-derived, UTXO-based, proof-of-work cryptocurrency that uses post-quantum signatures from genesis and extends PQ design into wallet derivation, script hashing, encrypted peer transport, and AuxPoW-ready merged mining.

That description is more precise than saying only “quantum resistant.” It tells developers and integrators what actually changed and what stayed Bitcoin-like.

Non-goals

Tidecoin does not claim that:

Non-goal	Reason
Quantum computers can never affect the network	Future cryptanalysis and engineering progress are unknown.
Every address format has the same PQ margin	Legacy compatibility formats and witness v1 have different hash properties.
Transport encryption hides the blockchain	Blocks and confirmed transactions remain public.
AuxPoW security exists without miner adoption	Merged mining needs real pool/miner participation.
Being Bitcoin-derived removes all consensus risk	Consensus changes still require review, tests, and cautious activation.

Source of truth

Topic	Source
Full-stack design statement	`../tidecoin/doc/whitepaper.md`
PQHD details	`../tidecoin/doc/design/pqhd.md`, PQHD
Signature scheme details	Falcon, ML-DSA
Script and witness extensions	Scripts, Witness V1 SHA-512
PoW and AuxPoW	Proof-of-Work, AuxPoW
Security boundaries	Security Analysis