As we know memory wallets more specifically Brainwallet 1.0 is a failed technology. I want to know how secure is this wallet system? It uses blockchain transaction hash and passphrase to calcualte entropy from which you can generate your private keys/mnemonic codes. As claimed by the creator of the wallet this can be super easy to memorize the few data precisely saying 4 numbers/words rather than 12 mnemonic phrases. Additionally the user can train himself visually until he memorizes.