Hi there Linhaidu! This is Brasseur Pepijn, co-founder of Etcetera. This is a very good question, and the answer is simple. The cards will be produced in a closed environment on a closed circuit computer with high security measures. This environment will be mainly automated and the software in charge of printing the cards will automatically destroy each private key after printing the card. There can only be one person with access to this computer at any moment, and this person will carry full responsability. When leaving the facility, the people involved in the proces will have safety checks to ensure no private keys or data will be stolen. These are pretty standard safety measures which are applied in companies around the world. Secondly, upon distribution the cards are empty wallets, and the private keys are protected by a scratch-off layer. As long as the scratch-off layer is still intact, the integrity of the card is preserved. If the scratch layer is not intact, the card cannot be sold and must be destroyed. But our packaging will not make it possible to remove the card, scratch of the layer to copy the code and put the card back. Once the card is removed from the package, it cannot be sold anymore to a new customer.