Abstract: A method of encrypting a passcode is disclosed. In one embodiment, the method includes: receiving an indication of a portion of the passcode; calculating a plaintext value based at least in part on the indication, wherein the plaintext value represents an encoded portion of the passcode; encrypting the plaintext value into ciphertext using a homomorphic encryption system; and updating a cumulative encryption string by executing a cumulative operation to aggregate the ciphertext corresponding to the encoded portion into the cumulative encryption string computed for a previous portion of the passcode, wherein the cumulative operation is dictated by a homomorphic property of the homomorphic encryption system.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining, at a remote computing device, whether a first security measure has been compromised, wherein the first security measure is executed on a mobile device; and based on a determination that the first security measure has been compromised, performing a corrective measure, wherein the corrective measure is performed after a delay.

Abstract: A method of encrypting sensor input entries for passcode entry security is disclosed. The method in one embodiment includes presenting a passcode entry interface on an electronic device for a user to input a passcode entry. The electronic device then receives an input event, which is indicative of at least part of the passcode entry by the user, from a sensor of the electronic device. The electronic device then encrypts a sensor value of the input event and transmits the encrypted sensor value to an external system over a network to cause the external system to decipher the passcode entry from the encrypted sensor value.

Abstract: A card reader configured to read a smart card can be detachably connected to a mobile computing device. When the card reader is attached to the mobile device, an application installed on the mobile computing device permits the mobile device to communicate with the card reader in order to process transactions. Security measures can be used on the mobile device to prevent theft of a PIN during software PIN entry of a payment transaction. The mobile device can prevent the keypad or other input interface from displaying feedback. The mobile device can also prevent passcodes from being stolen by displaying media encoded with digital rights management (DRM) and by managing the media and user inputs at a secure server. A mobile device can securely communicate with a card reader for a payment transaction using asymmetric or symmetric encryption.

Abstract: A card reader configured to read a smart card can be detachably connected to a mobile computing device. When the card reader is attached to the mobile device, an application installed on the mobile computing device permits the mobile device to communicate with the card reader in order to process transactions. Security measures can be used on the mobile device to prevent theft of a PIN during software PIN entry of a payment transaction. The mobile device can prevent the keypad or other input interface from displaying feedback. The mobile device can also prevent passcodes from being stolen by displaying media encoded with digital rights management (DRM) and by managing the media and user inputs at a secure server. A mobile device can securely communicate with a card reader for a payment transaction using asymmetric or symmetric encryption.

Abstract: A card reader configured to read a smart card can be detachably connected to a mobile computing device. When the card reader is attached to the mobile device, an application installed on the mobile computing device permits the mobile device to communicate with the card reader in order to process transactions. Security measures can be used on the mobile device to prevent theft of a PIN during software PIN entry of a payment transaction. The mobile device can prevent the keypad or other input interface from displaying feedback. The mobile device can also prevent passcodes from being stolen by displaying media encoded with digital rights management (DRM) and by managing the media and user inputs at a secure server. A mobile device can securely communicate with a card reader for a payment transaction using asymmetric or symmetric encryption.

Abstract: A card reader configured to read a smart card can be detachably connected to a mobile computing device. When the card reader is attached to the mobile device, an application installed on the mobile computing device permits the mobile device to communicate with the card reader in order to process transactions. Security measures can be used on the mobile device to prevent theft of a PIN during software PIN entry of a payment transaction. The mobile device can prevent the keypad or other input interface from displaying feedback. The mobile device can also prevent passcodes from being stolen by displaying media encoded with digital rights management (DRM) and by managing the media and user inputs at a secure server. A mobile device can securely communicate with a card reader for a payment transaction using asymmetric or symmetric encryption.