Randomness for encryption operations

摘要

Methods, systems, and computer programs for generating random values for encryption operations are described. In some examples, information from a message to be encrypted can be used to refresh the state of a pseudorandom generator. In some aspects, a state parameter of the pseudorandom generator is modified based on information in the message. Modifying the state parameter changes the state parameter from a prior state to a refreshed state based on the information in the message. A random output value is obtained by the pseudorandom generator in the refreshed state. The message is encrypted based on the random output value.

主权项

1. A computer-implemented encryption method, comprising:
accessing a message, by a data processing device, wherein accessing the message comprises extracting a portion of the message; modifying a state parameter of a pseudorandom generator implemented by the data processing device, wherein modifying the state parameter changes the state parameter from a prior state value of the pseudorandom generator to a refreshed state value of the pseudorandom generator using the extracted portion of the message and the prior state value of the pseudorandom generator; obtaining, by the data processing device, a random output value by the pseudorandom generator using the refreshed state value; encrypting, by the data processing device, the message using the random output value, wherein the message includes the extracted portion of the message; and sending the encrypted message to a recipient.