Abstract: In an embodiment, a system is provided in which the private key is managed in hardware and is not visible to software. The system may provide hardware support for public key generation, digital signature generation, encryption/decryption, and large random prime number generation without revealing the private key to software. The private key may thus be more secure than software-based versions. In an embodiment, the private key and the hardware that has access to the private key may be integrated onto the same semiconductor substrate as an integrated circuit (e.g. a system on a chip (SOC)). The private key may not be available outside of the integrated circuit, and thus a nefarious third party faces high hurdles in attempting to obtain the private key.

Abstract: Some embodiments provide non-transitory machine-readable medium that stores a program which when executed by at least one processing unit of a device synchronizes a set of keychains stored on the device with a set of other devices. The device and the set of other devices are communicatively coupled to one another through a peer-to-peer (P2P) network. The program receives a modification to a keychain in the set of keychains stored on the device. The program generates an update request for each device in the set of other devices in order to synchronize the set of keychains stored on device with the set of other devices. The program transmits through the P2P network the set of update requests to the set of other devices over a set of separate, secure communication channels.

Abstract: Some embodiments provide a method for a first device to synchronize a set of data items with a second device. The method receives a request to synchronize the set of data items stored on the first device with the second device. The method determines a subset of the synchronization data items stored on the first device that belong to at least one synchronization sub-group in which the second device participates. Participation in at least one of the synchronization sub-groups is defined based on membership in at least one verification sub-group. The first and second devices are part of a set of related devices with several different verification sub-groups. The method sends only the subset of the synchronization data items that belong to at least one synchronization sub-group in which the second device participates to the second device using a secure channel.

Abstract: A method of restoring confidential information items of a first device to a second device by using a set of servers. The method generates a public and private key pair and ties the private key to the hash of executable code of the servers at the time of generating the public and private keys. The method receives the encrypted confidential information items in a secure object which is encrypted with a user-specific key and the public key. The method only provides the confidential information to the second device when the second device provides the same user-specific key as the key that encrypts the secure object and the hash of the executable code of the servers at the time of accessing the private key to decrypt the secure object matches the hash of the executable code running on the servers at the time of generating the private key.

Abstract: Some embodiments provide convenient auto-authentication for user data on a primary device, while still providing a significant level of security, by taking advantage of existing security and cryptographic measures used to communicate with a secondary device. The primary device of some embodiments encrypts the user data on the primary device using a cryptographic key based on a set of keys received from the secondary device. In some embodiments, the primary device encrypts authentication data, or a local key generated from the authentication data, using a remote key received from the secondary device, and encrypts the user data with the local key. In some embodiments, the keys received from the secondary device are an existing set of keys for establishing an encrypted channel of communication for transmitting digital rights management (DRM) protected content according to a DRM protection scheme.

Abstract: Some embodiments provide a method for establishing a secured session with backward security between a first device and a second device. In some embodiments, the method establishes a communication session between the first and second devices using shared keys stored at the first and second devices. The method exchanges encrypted data between the first and second devices as a part of the communication session. The method, upon completion of the communication session, modifies the shared key at the first device in a predictable way. The shared key is modified at the second device in the same predictable way. The method then stores the modified shared key at the first device. The modified shared key cannot be used to decrypt any portion of the encrypted data of the current and previous communication sessions.

Abstract: A system for provisioning credentials onto an electronic device is provided. The system may include a payment network subsystem, a service provider subsystem, and one or more user devices that can be used to perform mobile transactions at a merchant terminal. The user device may communicate with the service provider subsystem in order to obtained commerce credentials from the payment network subsystem. The user device may include a secure element and a corresponding trusted processor. The trusted processor may generate a random authorization number and inject that number into the secure element. Mobile payments should only be completed if the random authorization number on the secure element matches the random authorization number at the trusted processor. The trusted processor may be configured to efface the previous random authorization number and generate a new random authorization number when detecting a potential change in ownership at the user device.

Abstract: In an embodiment, a system is provided in which the private key is managed in hardware and is not visible to software. The system may provide hardware support for public key generation, digital signature generation, encryption/decryption, and large random prime number generation without revealing the private key to software. The private key may thus be more secure than software-based versions. In an embodiment, the private key and the hardware that has access to the private key may be integrated onto the same semiconductor substrate as an integrated circuit (e.g. a system on a chip (SOC)). The private key may not be available outside of the integrated circuit, and thus a nefarious third party faces high hurdles in attempting to obtain the private key.

Abstract: Some embodiments provide a method for a first device that identifies definitions of different groups of devices, each of which is defined by a set of properties required for a device to be a member. The method monitors properties of the first device to determine when the device is eligible for membership in a group. When the first device is eligible for membership in a first group of which the device is not a member, the method sends an application for membership in the first group signed with at least a private key of the device to at least one other device that is a member of the first group. When the first device becomes ineligible for membership in a second group of which the first device is a member, the method removes the device from the second group and notifies other devices that are members of the second group.

Abstract: In some embodiments, a first device performs ranging operations to allow a user to perform one or more operations on the first device without providing device-access credentials. For example, when a second device is within a first distance of the first device, the first device determines that the second device is associated with a first user account that is authorized to perform operations on the first device. In response to the determination, the first device enables at least one substitute interaction (e.g., a password-less UI interaction) to allow the operations to be performed on the first device to be accessed without receiving access credentials through a user interface. In response to detecting an occurrence of the substitute interaction, the operation is authorized on the first device.

Abstract: Some embodiments provide a method for a first device to join a group of related devices. The method receives input of a password for an account with a centralized entity and a code generated by a second device in the group. When the second device determines that the code input on the first device matches the generated code, the method receives an authentication code from the second device for authorizing the first device with the entity as a valid device for the account. The method uses the password and information regarding the first device to generate an application to the group. After sending the application to the second device, the method receives information from the second device that enables the first device to add itself to the group. The second device verifies the generated application, and the method uses the information received from the second device to join the group.

Abstract: Techniques are disclosed relating to securely storing data in a computing device. In one embodiment, a computing device includes a secure circuit configured to maintain key bags for a plurality of users, each associated with a respective one of the plurality of users and including a first set of keys usable to decrypt a second set of encrypted keys for decrypting data associated with the respective user. The secure circuit is configured to receive an indication that an encrypted file of a first of the plurality of users is to be accessed and use a key in a key bag associated with the first user to decrypt an encrypted key of the second set of encrypted keys. The secure circuit is further configured to convey the decrypted key to a memory controller configured to decrypt the encrypted file upon retrieval from a memory.

Abstract: The subject technology may be implemented by a device that includes at least one processor configured to encrypt a data object based at least in part on an encryption key. The at least one processor may be further configured to sign the encrypted data object with a private key and transmit the signed encrypted data object to a server for retrieval by another device. The at least one processor may be further configured to generate a sharing object corresponding to the data object, wherein the sharing object includes an encryption key and a public key that corresponds to the private key. The at least one processor may be further configured to encrypt the sharing object using a key of the other device and transmit, over a secure channel, the encrypted sharing object to the other device for subsequent retrieval and verification of the signed data object from the server.

Abstract: Some embodiments provide a method for a first device for joining a group of related devices. The method receives input of a password for authorization with a centralized entity. The method receives input of a code generated by a second device already established in the group of related devices. The method uses the password and the code to (i) join the group of related devices in order to synchronize user data with the devices in the group of related devices and (ii) authorize the first device with the centralized entity as a valid device for a particular account with the centralized entity.

Abstract: Some embodiments provide a method for a first device to synchronize a set of data items with a second device. The method receives a request to synchronize the set of data items stored on the first device with the second device. The method determines a subset of the synchronization data items stored on the first device that belong to at least one synchronization sub-group in which the second device participates. Participation in at least one of the synchronization sub-groups is defined based on membership in at least one verification sub-group. The first and second devices are part of a set of related devices with several different verification sub-groups. The method sends only the subset of the synchronization data items that belong to at least one synchronization sub-group in which the second device participates to the second device using a secure channel.

Abstract: Some embodiments provide non-transitory machine-readable medium that stores a program which when executed by at least one processing unit of a device synchronizes a set of keychains stored on the device with a set of other devices. The device and the set of other devices are communicatively coupled to one another through a peer-to-peer (P2P) network. The program receives a modification to a keychain in the set of keychains stored on the device. The program generates an update request for each device in the set of other devices in order to synchronize the set of keychains stored on device with the set of other devices. The program transmits through the P2P network the set of update requests to the set of other devices over a set of separate, secure communication channels.

Abstract: Some embodiments provide a method for establishing a secured session with backward security between a first device and a second device. In some embodiments, the method establishes a communication session between the first and second devices using shared keys stored at the first and second devices. The method exchanges encrypted data between the first and second devices as a part of the communication session. The method, upon completion of the communication session, modifies the shared key at the first device in a predictable way. The shared key is modified at the second device in the same predictable way. The method then stores the modified shared key at the first device. The modified shared key cannot be used to decrypt any portion of the encrypted data of the current and previous communication sessions.

Abstract: A method of restoring confidential information items of a first device to a second device by using a set of servers. The method generates a public and private key pair and ties the private key to the hash of executable code of the servers at the time of generating the public and private keys. The method receives the encrypted confidential information items in a secure object which is encrypted with a user-specific key and the public key. The method only provides the confidential information to the second device when the second device provides the same user-specific key as the key that encrypts the secure object and the hash of the executable code of the servers at the time of accessing the private key to decrypt the secure object matches the hash of the executable code running on the servers at the time of generating the private key.

Abstract: Some embodiments provide a method for a first device that identifies definitions of different groups of devices, each of which is defined by a set of properties required for a device to be a member. The method monitors properties of the first device to determine when the device is eligible for membership in a group. When the first device is eligible for membership in a first group of which the device is not a member, the method sends an application for membership in the first group signed with at least a private key of the device to at least one other device that is a member of the first group. When the first device becomes ineligible for membership in a second group of which the first device is a member, the method removes the device from the second group and notifies other devices that are members of the second group.

Abstract: Some embodiments of the invention provide a method for a trusted (or originator) device to modify the security state of a target device (e.g., unlocking the device) based on a securing ranging operation (e.g., determining a distance, proximity, etc.). The method of some embodiments exchanges messages as a part of a ranging operation in order to determine whether the trusted and target devices are within a specified range of each other before allowing the trusted device to modify the security state of the target device. In some embodiments, the messages are derived by both devices based on a shared secret and are used to verify the source of ranging signals used for the ranging operation. In some embodiments, the method is performed using multiple different frequency bands.