Method of using one device to unlock another device

Abstract

A method of unlocking a second device using a first device is disclosed. The method can include: the first device pairing with the second device; establishing a trusted relationship with the second device; authenticating the first device using a device key; receiving a secret key from the second device; receiving a user input from an input/output device; and transmitting the received secret key to the second device to unlock the second device in response to receiving the user input, wherein establishing a trusted relationship with the second device comprises using a key generated from a hardware key associated with the first device to authenticate the device key.

What is claimed is: 
     
         1 . A method of unlocking a second device from a first device, comprising:
 establishing a trusted relationship with the second device;   authenticating the first device using a device key;   receiving a secret key from the second device;   receiving user input from an input/output device; and   transmitting the received secret key to the second device to unlock the second device in response to receiving the user input,   wherein establishing the trusted relationship with the second device comprises using a key generated from a hardware key associated with the first device to authenticate the device key.   
     
     
         2 . The method of  claim 1 , wherein prior to establishing the trusted relationship with the first device, the method further comprises pairing the first device with the second device by displaying a code on a display to be captured by the second device. 
     
     
         3 . The method of  claim 2 , wherein pairing with the second device is done with a Bluetooth out-of-band key. 
     
     
         4 . The method of  claim 1 , wherein establishing the trusted relationship with the second device comprises sending a public key to the second device. 
     
     
         5 . The method of  claim 4 , wherein the public key comprises a device key generated from an instance secret, a UUID identifying a set of keys, and a private device hardware key. 
     
     
         6 . The method of  claim 4 , further comprising validating the public key using a key generated from a hardware key associated with the first device. 
     
     
         7 . The method of  claim 6 , wherein the hardware key is shared with the second device. 
     
     
         8 . The method of  claim 4 , wherein the public key is certified by a shared authority. 
     
     
         9 . The method of  claim 1 , further comprising authenticating the second device using a device key associated with the second device. 
     
     
         10 . The method of  claim 9 , wherein the device key associated with the second device is configured to indicate whether the second device has been unlocked before. 
     
     
         11 . A method performed at a second device for being unlocked by a first device, comprising:
 receiving a public device key from the first device;   signing the received public device key with a private device key associated with the second device;   sending a secret key to the first device;   receiving a passcode;   deriving a master key from the passcode;   encrypting the master key with the secret key;   receiving the secret key from the first device;   retrieving the master key using the received secret key; and   using the master key to perform an unlocking operation.   
     
     
         12 . The method of  claim 11 , further comprising authenticating the first device using a device ID associated with the first device. 
     
     
         13 . The method of  claim 11 , further comprising unlocking the second device using the passcode. 
     
     
         14 . The method of  claim 11 , wherein the secret key comprises a random key. 
     
     
         15 . The method of  claim 11 , wherein the private device key is configured to indicate whether the second device has been unlocked with a passcode before. 
     
     
         16 . A non-transitory computer-readable storage medium of a first device capable of unlocking a second device, the storage medium storing instructions which, when executed by a processor, perform a method comprising:
 authenticating the first device using a device key;   receiving a secret key from the second device;   processing a user input received from an input/output device of the first device; and   transmitting the received secret key to the second device to unlock the second device in response to the user input.   
     
     
         17 . The non-transitory computer-readable storage medium of  claim 16 , the method further comprising detecting whether the second device is within a Bluetooth range of the first device. 
     
     
         18 . The non-transitory computer-readable storage medium of  claim 16 , the method further comprising signing a first key with a second key. 
     
     
         19 . The non-transitory computer-readable storage medium of  claim 18 , wherein the first key comprises a device key and the second key comprises a SEP global key. 
     
     
         20 . The non-transitory computer-readable storage medium of  claim 16 , the method further comprising generating at least one of: a SEP global key, a device key, and a device unlock key. 
     
     
         21 . A non-transitory computer-readable storage medium of a second device capable of being unlocked by a first device, the storage medium storing instructions, which, when executed by a processor, perform a method comprising:
 receiving a public device key and a secret key from the first device;   signing the received public device key with a private device key associated with the second device;   sending a secret key to the first device;   processing a passcode;   deriving a master key from the passcode;   encrypting the master key with the secret key;   retrieving the master key using the received secret key; and   using the master key to perform an unlocking operation.   
     
     
         22 . The non-transitory computer-readable storage medium of  claim 21 , the method further comprising authenticating the first device using a device ID associated with the first device. 
     
     
         23 . The non-transitory computer-readable storage medium of  claim 21 , the method further comprising unlocking the second device using the passcode. 
     
     
         24 . A first device capable of unlocking a second device, the first device comprising:
 an authentication module configured for establishing a trusted relationship with the second device and authenticating the first device using a device key;   a receiving module configured for receiving a secret key from the second device;   a user input processing module configured for processing user input received from an input/output device; and   a transmitting module configured for transmitting the received secret key to the second device to unlock the second device in response to receiving the user input,   wherein establishing the trusted relationship with the second device comprises using a key generated from a hardware key associated with the first device to authenticate the device key.   
     
     
         25 . A second device capable of being unlocked by a first device, the second device comprising:
 a receiving module configured for receiving a public device key from the first device;   a key signing module configured for signing the received public device key with a private device key associated with the second device;   a transmitting module configured for sending a secret key to the first device;   a user input processing module configured for processing a passcode;   a deriving module configured for deriving a master key from the passcode;   an encrypting module configured for encrypting the master key with the secret key;   a receiving module for receiving the secret key from the first device and retrieving the master key using the received secret key; and   an unlocking module configured for using the master key to perform an unlocking operation.