The public key in the BTC is used as a collection address. The private key is known only to you, if it is be public or lost means that your assets will be lost. Therefore, the private key plays an important role in our assets. Although the registration of the TokenPocket wallet started as a remind of backup and verification mnemonic(equally important), the backup of the private key means that we can have more controllable keys. If one of the two is lost, the asset will not be lost.