Proof-of-Work

Tidecoin uses a two-phase proof-of-work. Phase 1 is YespowerTIDE (N=2048, r=8), a memory-hard algorithm from the yespower family optimized for CPU L2 cache access patterns. Phase 2 activates with AuxPoW: Tidecoin accepts scrypt solutions from Litecoin’s parent chain (chain ID 8), inheriting Litecoin’s established hashrate.

This page is the protocol-level proof-of-work overview. Mining setup belongs in Mining; AuxPoW structure belongs in AuxPoW.

Activation by network

Network	Pre-AuxPoW phase	Post-AuxPoW phase
Mainnet	Active	Built, not active while AuxPoW is disabled.
Testnet	Blocks before height 1000	Active from height 1000.
Regtest	Not the default phase	Active from genesis.

Phase 1: YespowerTIDE

Before AuxPoW activation, Tidecoin validates block work with the Tidecoin YespowerTIDE hash. The design goal of the launch phase was broad participation and memory-hard standalone mining during initial distribution.

Consensus and wallet-facing docs should treat this as the current mainnet phase, not as the long-term mining integration target. Current mining integration work is centered on scrypt merged mining through AuxPoW.

Phase 2: scrypt through AuxPoW

At AuxPoW activation height, UseScryptPoW(params, height) becomes true and Tidecoin validates block work using the scrypt proof carried by the parent AuxPoW header. The parent chain does not need to understand Tidecoin; Tidecoin verifies the AuxPoW commitment and parent proof.

AuxPoW activation simultaneously gates the broader post-AuxPoW ruleset:

Rule area	Before AuxPoW	At and after AuxPoW
PoW hash	YespowerTIDE	Scrypt parent proof through AuxPoW
Mining model	Standalone Tidecoin mining	Merged mining
Signature schemes	Falcon-512 only	Falcon-512, Falcon-1024, ML-DSA-44/65/87
Witness/script	Existing witness rules	Witness v1 / P2WSH-512 and OP_SHA512 enabled
PQ verification	Legacy-compatible Falcon-512 mode	Strict PQ verification flags enabled

Difficulty adjustment

Parameter	Pre-AuxPoW	Post-AuxPoW
Target block time	60 seconds	60 seconds
Retarget interval	7200 blocks, about 5 days	Every block
Method	Periodic legacy retarget	Averaging-window retarget using median time past
Averaging window	Not used	17 blocks
Max adjustment down	Period clamp	32 percent
Max adjustment up	Period clamp	16 percent
Mainnet min-difficulty blocks	Disabled	Disabled

The post-AuxPoW retarget path averages recent targets over a 17-block window and uses median time past to reduce timestamp manipulation.

Quantum-resistance rationale

The long-term merged-mining phase uses scrypt because memory-hard functions are less friendly to clean Grover-oracle construction than stateless hashes. Scrypt requires a scratchpad and data-dependent memory reads; a quantum oracle would need to represent and query that memory coherently, making the attack model far less direct than SHA-256d.

This is a security rationale, not a claim that proof-of-work alone solves every network security problem. Live security still depends on active hashrate, miner participation, pool behavior, network connectivity, and economic incentives.

Source of truth

Source	What it defines
`src/pow.cpp`	PoW hash switch, retarget behavior, target checks.
`src/kernel/chainparams.cpp`	Activation heights and PoW parameters per network.
`src/crypto/yespower/tidecoin_pow.*`	YespowerTIDE hash implementation.
`src/auxpow.*`	AuxPoW proof structure and checks.