US 12,457,201 B2
Method and system for privacy preserving information exchange based on aggregating masked vectors from local parties
Nicolas Ferland, Santa Clara, CA (US); James Donald Reno, Scotts Valley, CA (US); and Subramanian Iyer, Santa Clara, CA (US)
Assigned to Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
Appl. No. 17/797,221
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
PCT Filed Apr. 16, 2020, PCT No. PCT/IB2020/053635
§ 371(c)(1), (2) Date Aug. 3, 2022,
PCT Pub. No. WO2021/161079, PCT Pub. Date Aug. 19, 2021.
Prior Publication US 2023/0046255 A1, Feb. 16, 2023
Int. Cl. H04L 9/40 (2022.01); G06N 20/00 (2019.01)
CPC H04L 63/0414 (2013.01) [G06N 20/00 (2019.01); H04L 63/0428 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method implemented in an electronic device to serve as a local party for privacy preserving information exchange between the local party and another electronic device to serve as an aggregator, wherein the aggregator exchanges information with a plurality of local parties including the local party, wherein the exchanged information is decision tree information for decision tree learning, and wherein the aggregator is to generate a decision tree, the method comprising:
storing a plurality of values in a two-dimensional (2D) vector, wherein a first dimension of the 2D vector is based on how many values are in the plurality of values, and wherein each position in the first dimension has one unique value within the plurality of values, wherein each unique value within the plurality of values is in a randomly selected position in a second dimension, and wherein the plurality of values comprises a first plurality of split point value candidates for at least one feature of the decision tree;
transmitting the 2D vector to the aggregator with masking for the aggregator to prevent the aggregator from decoding the 2D vector to determine the plurality of values transmitted by the local party, wherein aggregating each position of the masked 2D vector with corresponding positions of masked 2D vectors from other local parties allows unmasking of the plurality of values in the 2D vector without identifying the local parties from which the values originated;
receiving a second plurality of split point value candidates from the aggregator; and
transmitting quantile sketch information mapped to the second plurality of split point value candidates of the feature to the aggregator with masking to prevent the aggregator from decoding the quantile sketch information, wherein aggregating the masked quantile sketch information with quantile sketch information from other local parties allows decoding of the aggregated quantile sketch information.