Whatsapp Inc.

Chun Wing Yuen

George Nachman

Ehren Andrew Kret

Eugene Fooksman

Dmitri Stukalov

Zafir Khan

Sergey Petrov

Derek Alan Konigsberg

Alexander Shturm

Techniques for key ratcheting with multiple step sizes are described. For example, an apparatus may be configured to receive two or more encrypted messages, where the encrypted messages are encrypted according to a multi-dimensional ratcheting encryption scheme. Moreover, the apparatus may be configured to determine which of the encrypted messages was most-recently received and extract a message iteration count from the most-recent encrypted message, generate a decrypted message by decrypting the encrypted message based on a decryption key, decompose the message iteration count into a plurality of message chain key iteration counts, and determine the decryption key based on the plurality of message chain key iteration counts.

Techniques for key ratcheting with multiple step sizes

A messaging server receives a sharing message from a sharer client indicating that the sharer client is offering to provide live location information. When the messaging server receives a subscription request from a receiver client indicating a request to receive live location information shared by the sharer client, the messaging server sends a location request to the sharer client. The location request requests live location information from the sharer client. The sharer client determines its location using a location module and sends live location information to the messaging server in response to the request. The server sends the live location information received from the sharer client to the receiver client. When no receiver clients send subscription requests, the sharer client does not send live location information, thereby preserving power by limiting use of the location module.

Power management for location sharing

Growing community of inventors

Foster City, CA, United States of America

Chun Wing Yuen