In StarkEx, Registration means mapping the user
starkKey to his Ethereum Address. This mapping enforces that when funds are removed from an L2 account, only the Ethereum address registered to that account's
starkKey will be able to withdraw the funds on-chain.
Alice requests the application operator to register her
starkKey under her Ethereum address. If the application chooses to register Alice (each application can have its own registration policy), it signs the mapping with the
A transaction is sent to the StarkEx contract, containing the Ethereum address, the
starkKey and the signature obtained during the previous step. See register for more information on this function.