Protocol for protecting content protection data
AssigneeResearch In Motion Limited
InventorsVan Quy TU, Herbert Anthony LITTLE, Kristof TAKACS
Life of this patent
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Abstract
Through the use of a one-time-use nonce, the transfer of cryptographic data over a potentially insecure link in a two-factor content protection system is avoided. The nonce may be stored encrypted with a public key from a smart card. A random key may be used to produce a storage key, which is used to encrypt a content protection key. The random key may be stored, encrypted with a key derived from the nonce. Instead of receiving a raw content protection key over the potentially insecure link, the raw nonce is received and, once used, replaced with a new nonce.
Claims20
At an apparatus with a persistent memory, a method of facilitating multi-factor protection for at least some raw data stored in said persistent memory, said method comprising:
- generating a random key;
- generating a random nonce;
- generating, based on said random nonce, a derived key;
- encrypting, using said derived key, said random key, thereby producing an encrypted random key;
- storing, in said persistent memory, said encrypted random key;
- receiving a device password for said apparatus;
- generating, based on said device password and said random key, a storage key;
- generating a content protection key;
- encrypting, using said content protection key, said raw data, thereby producing encrypted data;
- storing, in said persistent memory in place of said raw data, said encrypted data;
- encrypting, using said storage key, said content protection key, thereby producing an encrypted content protection key;
- and
- storing, in said persistent memory, said encrypted content protection key.
An apparatus comprising:
- a persistent memory storing raw data;
- and
- a processor operable to:
- generate a random key;
- generate a random nonce;
- generate, based on said random nonce, a derived key;
- encrypt, using said derived key, said random key, thereby producing an encrypted random key;
- store, in said persistent memory, said encrypted random key;
- receive a device password for said apparatus;
- generate, based on said device password and said random key, a storage key;
- generate a content protection key;
- encrypt, using said content protection key, said raw data, thereby producing encrypted data;
- store, in said persistent memory in place of said raw data, said encrypted data;
- encrypt, using said storage key, said content protection key, thereby producing an encrypted content protection key;
- and
- store, in said persistent memory, said encrypted content protection key.
A computer-readable medium containing computer-executable instructions that, when performed by a processor for facilitating multi-factor protection for at least some raw data stored in a persistent memory, cause said processor to:
- generate a random key;
- generate a random nonce;
- generate, based on said random nonce, a derived key;
- encrypt, using said derived key, said random key, thereby producing an encrypted random key;
- store, in said persistent memory, said encrypted random key;
- receive a device password for said apparatus;
- generate, based on said device password and said random key, a storage key;
- generate a content protection key;
- encrypt, using said content protection key, said raw data, thereby producing encrypted data;
- store, in said persistent memory in place of said raw data, said encrypted data;
- encrypt, using said storage key, said content protection key, thereby producing an encrypted content protection key;
- and
- store, in said persistent memory, said encrypted content protection key.
Dependencies are inferred from the claim text.