摘要:
Methods and apparatus for verifying that an electronic device has been disabled are disclosed. An exemplary electronic device includes a communications interface, a secure memory, storing a secret key, and a cryptographic circuit configured to calculate a verification token from the secret key, using a first cryptographic operation. The cryptographic circuit is further configured to calculate an identification token from the verification token, using a second cryptographic operation. The cryptographic circuit is further configured to output the identification token in response to a first command received via the communications interface. The verification token is output to the communications interface only if a predetermined functionality of the electronic device has been disabled. The electronic device may further comprise a disabling circuit configured to disable the predetermined functionality in response to a disable command.
摘要:
The invention relates to a method for enabling modifications of integrity protected data, such as SIM lock settings, in a device. The method comprises: in a device, creating a data entity containing signed change information about allowable alterations, the change information being bound to the device, a certificate with a public key corresponding to the private key used to sign the change information; accessing the device and requesting alteration; verifying the requested alteration against the data entity; and if the verification succeeds, performing the requested alteration. By centrally preparing dedicated replacement devices, which locally can be altered in a simple and secure way, without compromising sensitive information or data, a more secure handling of alteration is achieved. Also, the invention relates to a corresponding computer program product and a device implementing the method.
摘要:
An electronic device requires valid control keys to change any usage restriction setting. The device is provided control keys, a secret key, and a signed software object including a batch ID and a hash of the secret key. For each control key, the device generates a cryptographic footprint bound to the device and the secret key. A message authentication code (MAC) of each usage restriction setting is generated, the MAC bound to the device and a control key. To change a usage restriction, the device receives a control key, validates it against the stored footprint, changes the usage restriction settings, and generates a new usage restriction setting MAC. The control key footprints are bound to the secret key, but the device retains only a hash of the secret key.
摘要:
Digital rights management is described involving a device, a content issuer, and a rights issuer. A content encryption key (CEK) is encrypted using a public key associated with the device to produce an encrypted CEK. The encrypted CEK is encrypted using an issuer encryption key to produce a twice encrypted CEK. The twice encrypted CEK is encrypted using the public key to produce a ciphertext included in a rights object. The rights object is available to the device for decrypting digital content associated with the content issuer. The device can then decrypt the rights object ciphertext using its private key to produce a decrypted rights object ciphertext and decrypt the decrypted rights object ciphertext using an issuer decryption key received from the content issuer to produce an encrypted CEK. The encrypted CEK is decrypted using the private key to obtain the CEK, which is then available for decrypting digital content.
摘要:
A composite customer ID (CCID) is stored in the OTP memory of integrated circuit chipsets used by a number of different customers. The CCID includes individual customer IDs (CIDs) at defined index positions, each corresponding to a different customer. Each chipset allows or disallows software booting, based reading a certificate index value from a given customer's certificate, reading an OTP CID from OTP, as pointed to the by certificate index value, and evaluating the OTP CID with a certificate CID read from the certificate. Thus, while CCID carries information for a plurality of customers, each customer's certificate points only to that customer's OTP CID, which can be changed to revoke that customer's certificate without revoking the other customers' certificates. The CCID also may include a version number, where the chipsets allow or disallow software booting based on evaluating the certificate version number in view of the CCID version number.
摘要:
A system for heating liquid using solar radiation, includes a plurality of solar panels (1, 2, 3, 4, 5), at least one reservoir for heated liquid and pipes for circulating liquid between the respective solar panel and the at least one liquid reservoir, the liquid circulating by gravity circulation. The present system is characterised in that a non-return valve (17) for controlling the flow of heated liquid from the respective solar panel is placed in a portion of the circulation pipe between the upper end of the solar panel and the at least one liquid reservoir, the non-return valve (17) being adapted to open and close at a predetermined pressure in the liquid flow from the solar panel.