Best way to make a multisig address unique?

[jeffg]

Sorry, posted in the wrong forum. Moved to https://bitcointalk.org/index.php?topic=558294

[Abdussamad]

Use a BIP32 wallet for your site. Publish an extended public key. Then you extend that public key with the project ID to derive the public key for that project. Anyone can verify the public key using standard bip32 software and you get unique addresses per project.