Stream cipher encryption and message authentication
AssigneeQUALCOMM Incorporated
InventorsPhillip Hawkes, Michael Paddon, Gregory Gordon Rose
Life of this patent
Estimating the term…
Abstract
Stream cipher encryption and message authentication. Stream cipher encryption is performed by generating a keystream at the transmitting end from a state value, applying the keystream to plaintext to generate an encrypted message block having at least a portion of the plaintext converted to ciphertext, and updating the state value as a function of said at least a portion of the plaintext. Stream cipher decryption is performed by generating a keystream at the receiving end from the same state value, applying the keystream to the encrypted message block to convert the ciphertext to plaintext, and updating the state value as a function of the plaintext. Message authentication techniques are also described.
Claims42
An encryption module, comprising:
- a storage medium configured to store a state value;
- and a processor configured to generate a keystream from the state value, and apply the keystream to plaintext to generate an encrypted message block having at least a portion of the plaintext converted to ciphertext, and wherein the processor is further configured to update the state value in the storage medium as a function of said at least a portion of the plaintext.
A decryption module, comprising:
- a storage medium configured to store a state value;
- and a processor configured to generate a keystream from the state value, and apply the keystream to an encrypted message block to convert ciphertext to plaintext, and wherein the processor is further configured to update the state value in the storage medium as a function of the plaintext.
A method of encryption, comprising:
- generating a keystream from a state value;
- applying the keystream to plaintext to generate an encrypted message block having at least a portion of the plaintext converted to ciphertext;
- and updating the state value in the storage medium as a function of said at least a portion of the plaintext.
A method of decryption, comprising:
- generating a keystream from the state value;
- applying the keystream to an encrypted message block to convert ciphertext to plaintext;
- and updating the state value in the storage medium as a function of the plaintext.
Computer readable media embodying a program of instructions executable by a processor to perform a method of encryption, the method comprising:
- generating a keystream from a state value;
- applying the keystream to plaintext to generate an encrypted message block having at least a portion of the plaintext converted to ciphertext;
- and updating the state value in the storage medium as a function of said at least a portion of the plaintext.
Computer readable media embodying a program of instructions executable by a processor to perform a method of decryption, the method comprising:
- generating a keystream from the state value;
- applying the keystream to an encrypted message block to convert ciphertext to plaintext;
- and updating the state value in the storage medium as a function of the plaintext.
An encryption module, comprising:
- means for generating a keystream from a state value;
- means for applying the keystream to plaintext to generate an encrypted message block having at least a portion of the plaintext converted to ciphertext;
- and means for updating the state value in the storage medium as a function of said at least a portion of the plaintext.
A decryption module, comprising:
- means for generating a keystream from the state value;
- means for applying the keystream to an encrypted message block to convert ciphertext to plaintext;
- and means for updating the state value in the storage medium as a function of the plaintext.
Dependencies are inferred from the claim text.