Ballet Cold Storage private keys are created using the BIP38 open-source standard, which has been used throughout the cryptocurrency industry for years and has proven to be secure. BIP38 includes a verification process where a confirmation code can be used to verify the cryptographic integrity of private key entropies. Every Ballet Cold Storage that we manufacture is checked using this verification method. In addition, our quality control process involves random spot-checks of finished cards, where we remove the tamper-evident protections and actually test the encryption to ensure that any coins deposited to the cold storage can be sent out. Once we check these cards, they are destroyed and disposed of.