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Key Derivation
StarkWare recommends two methods for
starkPrivateKey derivation:- BIP32 compatible wallets should implement EIP-2645. In this context, wallets are expected to be stateful of their own Ethereum address.
- Non BIP32 wallets should implement the methodology presented at the bottom of the current page
The
starkKey value derives from a path called starkPath that consists of four passed parameters and two internal parameters as described below, and has the following structure: m/purpose'/layer'/application'/ethAddress1'/ethAddress2'/indexPassed parameters
- purpose -
2645 - layer - Differentiate between technologies, defined as
sha256(layer) & ((1 << 31) - 1)) - application - Differentiate applications, defined as
sha256(application) & ((1 << 31) - 1)) - index - Allow multiple keys per Ethereum address
Internal parameters
- ethAddress1 - 31 LSB of the user ethereum address (i.e.
ethAddress & ((1 << 31) - 1)) - ethAddress2 - 31 following LSB of the user ethereum address (i.e.
(ethAddress >> 31) & ((1 << 31) - 1))
Derivation methodology for BIP32 wallets
Derivation methodology for non-BIP32 wallets
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pk = Ethereum Private Key
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sign = ECDSA on secp256k1
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ethAddress1 = ethAddress & ((1 << 31) - 1)
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ethAddress2 = (ethAddress >> 31 ) & ((1 << 31) - 1)
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N = secp256k1 curve order
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n = Layer2 curve order (available in the cryptography section)
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path = "m/purpose'/layer'/application'/ethAddress1'/ethAddress2'/index"
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i = 0
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root_key = bip39
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.fromSecret(pk).derivePath(path)
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.getWallet()
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.getPrivateKeyString()
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while True:
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key = _hash(root_key.to_bytes(32,byteorder='big') + i.to_bytes(1,byteorder='big'))
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if (key < (N - (N % n))):
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return key % n
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i++
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Last modified 1mo ago