Public key encryption algorithms for hard lock file encryption
AssigneesBlackBerry Limited, Certicom Corp.
InventorsRobert John Lambert, Daniel Richard L. Brown, Atsushi Yamada
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Abstract
In some aspects, an encryption method comprises encrypting a first portion of a message using a first secret key. The first secret key is generated based on the public key of an entity. A one-way function is used to generate a second secret key from the first secret key, and the first secret key is subsequently discarded. A second portion of the message is encrypted using the second secret key. The encrypted first portion of the message and the encrypted second portion of the message are provided to the entity.
Claims14
A public key encryption method comprising:
- generating a shared secret based on a public key of an entity and an ephemeral private key;
- using a key derivation function to generate a first secret key from the shared secret;
- encrypting, by operation of a computing device, a first portion of a message using the first secret key;
- using the key derivation function to generate a second secret key from the first secret key;
- discarding the first secret key;
- encrypting, by operation of the computing device, a second portion of the message using the second secret key;
- providing an ephemeral public key associated with the ephemeral private key to the entity;
- and
- providing the encrypted first portion of the message and the encrypted second portion of the message to the entity.
A non-transitory computer-readable medium comprising instructions that are operable when executed by data processing apparatus to perform public key encryption operations comprising:
- generating a shared secret based on a public key of an entity and an ephemeral private key;
- using a key derivation function to generate a first secret key from the shared secret;
- encrypting a first portion of a message using the first secret key;
- using the key derivation function to generate a second secret key from the first secret key;
- discarding the first secret key;
- encrypting a second portion of the message using the second secret key;
- providing the encrypted first and second portions of the message to the entity;
- and
- providing an ephemeral public key associated with the ephemeral private key to the entity.
A device comprising:
- one or more processors operable to decrypt a public-key encrypted message by performing operations comprising:
- accessing an encrypted message, the encrypted message having been encrypted using multiple secret keys based on a public key of an entity;
- generating a shared secret based on an ephemeral public key and a private key of the entity;
- using a key derivation function to generate a first secret key based on the shared secret;
- decrypting a first portion of the message using the first secret key;
- using the key derivation function to generate a second secret key from the first secret key;
- and
- decrypting a second portion of the message using the second secret key.
Dependencies are inferred from the claim text.