Abstract: A cryptographic system includes an online computer, an offline computer and custom hardware and software by which the two computers can securely communicate to facilitate the creation, secure use, and maintenance of private cryptographic keys. The system securely stores private cryptographic keys while still enabling the keys to be quickly and easily accessed as needed in a variety of applications including, but not limited to, electronic financial transactions, cryptographic transaction processing, medical record access, email encryption, or any other cryptographic authentication process.