How to setup a Litecoin + Bitcoincoin merge mining? (AuxPow)

Merge Mining Concept and Core Mechanics

1. Merge mining allows a miner to simultaneously mine two or more cryptocurrencies using the same computational work without additional energy cost.

2. Litecoin adopted Auxiliary Proof-of-Work (AuxPoW) in 2014, enabling miners to embed Litecoin block headers into Bitcoin blocks as auxiliary data.

3. Dogecoin implemented AuxPoW in 2014 as well, but its implementation differs slightly in header structure and coinbase transaction handling compared to Litecoin.

4. Both chains validate the parent chain’s proof-of-work—Bitcoin for Litecoin, and Litecoin for Dogecoin—making the security model hierarchical.

5. A valid AuxPoW block must contain a valid parent-chain block hash, a merkle path proving inclusion of the child block header, and correct signature verification using the parent chain’s coinbase output script.

Required Software Stack and Compatibility

1. You need a full Bitcoin Core node running version 22 or higher to serve as the parent chain for Litecoin’s AuxPoW mining.

2. Litecoin Core must be compiled with --enable-auxpow flag and linked against a compatible version of libbitcoinconsensus.

3. Dogecoin Core requires compilation with --enable-auxpow and must be configured to recognize Litecoin as its parent chain—not Bitcoin.

4. Stratum proxy software like litecoin-stratum or custom forks of ckpool are necessary to route shares correctly across both chains.

5. GPU or ASIC miners must support stratum v2 or extended auxpow-enabled stratum extensions; standard cgminer or bfgminer builds will not suffice without patches.

Node Configuration and Chain Synchronization

1. Start Bitcoin Core with -server -txindex -rpcuser=mine -rpcpassword=pass and ensure it reaches full synchronization.

2. Launch Litecoin Core with -server -txindex -rpcuser=ltc -rpcpassword=pass -auxpow=1 -connect=127.0.0.1:8333 to link to Bitcoin.

3. Run Dogecoin Core with -server -txindex -rpcuser=doge -rpcpassword=pass -auxpow=1 -connect=127.0.0.1:9333, pointing to Litecoin’s RPC port.

4. Verify chain heights using getblockcount on each daemon; mismatched heights indicate sync failure or misconfigured peers.

5. Check AuxPoW status via getmininginfo—the “auxpow” field must return true, and “pooledtx” should reflect non-zero values when hashing.

Stratum Proxy Setup and Share Routing

1. Deploy a patched version of ckpool that parses AuxPoW-specific fields such as parent-block-hash and merkle-tree depth.

2. Configure the proxy to accept submissions from miners, verify PoW against Bitcoin’s difficulty, then forward valid headers to both Litecoin and Dogecoin daemons.

3. Use separate stratum ports: 3333 for Litecoin-bound shares, 4444 for Dogecoin-bound shares, and ensure each port maps to correct coinbase addresses.

4. Enforce strict validation of coinbase outputs—Litecoin expects the first output to commit to its own block hash, while Dogecoin expects the second output to commit to its header.

5. Monitor logs for 'auxpow accepted' and 'doge aux relay success' messages to confirm cross-chain propagation.

Troubleshooting Common Failures

1. If Dogecoin rejects blocks with “bad-auxpow”, verify the Litecoin block used as parent contains a valid AuxPoW tag in its coinbase input script.

2. Stale shares often result from time skew between nodes—synchronize all daemons using ntpd or chrony with the same NTP server.

3. RPC authentication failures occur when passwords differ across daemons; reuse identical credentials or update config files to match exactly.

4. Missing merkle paths cause “invalid merkle root” errors—recompile Dogecoin Core with updated merkle tree serialization logic from recent Litecoin PRs.

5. ASIC firmware may drop AuxPoW fields silently—test submission manually using curl and raw JSON-RPC calls before deploying at scale.

Frequently Asked Questions

Q: Can I merge-mine Dogecoin and Litecoin without Bitcoin?A: No. Litecoin requires Bitcoin’s PoW as its parent chain. Dogecoin uses Litecoin as parent, forming a dependency chain: Bitcoin → Litecoin → Dogecoin.

Q: Does merge mining dilute security on either chain?A: No. Each chain independently validates the embedded proof. Security derives from the parent chain’s hashrate, not shared computation.

Q: Why does Dogecoin use Litecoin instead of Bitcoin directly?A: Dogecoin’s AuxPoW design predates Bitcoin’s native AuxPoW support. It was engineered to piggyback on Litecoin’s already-deployed infrastructure.

Q: Are merged blocks visible on both explorers?A: Yes. Valid AuxPoW blocks appear on Litecoin and Dogecoin block explorers with explicit “Auxiliary Proof-of-Work” labels and embedded parent hashes.