US Patent 10425224 Identity confirmation using private keys

Systems and methods for identify confirmation and transaction security are described. The system transmits to a client computing system an encrypted challenge generated using a public key of an asymmetric key pair and a first partially decrypted challenge generated by applying a first private key fragment of a private key of the asymmetric key pair to the encrypted challenge. The system receives a decrypted challenge generated by applying a second private key fragment of the private key to the encrypted challenge to generate a second partially decrypted challenge, applying a third private key fragment of the private key to the encrypted challenge to generate a third partially decrypted challenge, and combining the first partially decrypted challenge, the second partially decrypted challenge and the third partially decrypted challenge to generate the decrypted challenge. The system uses the decrypted challenge for verification.