Abstract: Apparatus and methods perform transactions in a secure environment between an individual and another party, such as a merchant, in various embodiments. The individual possesses a mobile electronic device, such as a smartphone, that can encrypt data according to a public key infrastructure. The individual authenticates the individual's identity to the device, thereby unlocking credentials that may be used in a secure transaction. The individual causes the device to communicate the credentials, in a secure fashion, to an electronic system of a relying party, in order to obtain the relying party's authorization to enter the transaction. The relying party system determines whether to grant the authorization, and communicates the grant and the outcome of the transaction to the device using encryption according to the public key infrastructure.