Add feature for Duplicate Key PIR

[yunbo99]

No description provided.

[github-actions]

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[gemini-code-assist]

Hello @yunbo99, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

Summary of Changes

This pull request introduces a new feature for Duplicate Key PIR (DkPir), which enables batch queries while preserving data privacy. The changes include adding necessary dependencies, example data, configuration files, and core logic for both sender and receiver sides. The implementation extends the existing APSI framework to support scenarios where the server-side database contains multiple rows with the same key, enabling applications like billable PIR.

Highlights

• Dependency Addition: The pull request adds heu as a bazel dependency in MODULE.bazel. This library is used for homomorphic encryption, a key component of the DkPir protocol.
• Example Data: New CSV files (duplicate_key_db.csv, duplicate_key_query.csv, duplicate_key_target_result.csv) are added to examples/pir/apsi/data/ to demonstrate the duplicate key PIR functionality. These files contain sample data and queries for testing the new feature.
• Configuration Files: New configuration files (dk_pir_receiver_online.json, dk_pir_sender_offline.json, dk_pir_sender_online.json) are added to examples/pir/config/ to define the settings for the DkPir sender and receiver in both online and offline modes. These configurations specify parameters like file paths, curve types, and communication settings.
• Core Logic Implementation: The pull request introduces a new directory psi/algorithm/dkpir/ containing the core logic for the DkPir protocol. This includes implementations for the sender, receiver, OPRF receiver, and common utilities, as well as a new proto definition for secret keys.
• CSV Conversion Utilities: The pull request adds a csv_converter library to psi/utils, providing utilities for converting CSV files into formats suitable for APSI and DkPir. This includes functionalities for merging columns and rows, extracting queries, and extracting results.

Changelog

Click here to see the changelog

• MODULE.bazel
  • Added heu as a bazel dependency.
• examples/pir/apsi/data/duplicate_key_db.csv
  • Added a CSV file containing example database with duplicate keys.
• examples/pir/apsi/data/duplicate_key_query.csv
  • Added a CSV file containing example queries for duplicate keys.
• examples/pir/apsi/data/duplicate_key_target_result.csv
  • Added a CSV file containing the expected results for the example queries.
• examples/pir/config/dk_pir_receiver_online.json
  • Added a configuration file for the DkPir receiver in online mode.
• examples/pir/config/dk_pir_sender_offline.json
  • Added a configuration file for the DkPir sender in offline mode.
• examples/pir/config/dk_pir_sender_online.json
  • Added a configuration file for the DkPir sender in online mode.
• psi/algorithm/dkpir/BUILD.bazel
  • Added a BUILD file for the dkpir algorithm, defining the necessary libraries and dependencies.
• psi/algorithm/dkpir/README.md
  • Added a README file describing the DkPir scheme, its application scenarios, and instructions for testing.
• psi/algorithm/dkpir/common.cc
  • Implemented common utility functions for DkPir, including polynomial computation, key saving/loading, and result writing.
• psi/algorithm/dkpir/common.h
  • Defined common data structures and function prototypes for DkPir.
• psi/algorithm/dkpir/encryptor.h
  • Defined a custom Elgamal encryptor without plaintext range restrictions.
• psi/algorithm/dkpir/entry.cc
  • Implemented entry points for the DkPir sender and receiver in both offline and online modes.
• psi/algorithm/dkpir/entry.h
  • Defined the entry point functions for the DkPir algorithm.
• psi/algorithm/dkpir/oprf_receiver.cc
  • Implemented the OPRF receiver component for DkPir.
• psi/algorithm/dkpir/oprf_receiver.h
  • Defined the OPRF receiver class for DkPir.
• psi/algorithm/dkpir/query.h
  • Defined the DkPirQuery class, extending the base apsi::sender::Query to include a sender count database.
• psi/algorithm/dkpir/receiver.cc
  • Implemented the DkPir receiver logic, including OPRF request handling and query processing.
• psi/algorithm/dkpir/receiver.h
  • Defined the DkPir receiver class.
• psi/algorithm/dkpir/secret_key.proto
  • Defined the protobuf message for storing secret keys.
• psi/algorithm/dkpir/sender.cc
  • Implemented the DkPir sender logic, including OPRF response generation and query processing.
• psi/algorithm/dkpir/sender.h
  • Defined the DkPir sender class.
• psi/algorithm/dkpir/sender_cnt_db.cc
  • Implemented the logic for generating the sender count database, including encryption of row counts.
• psi/algorithm/dkpir/sender_cnt_db.h
  • Defined the functions for generating the sender count database.
• psi/algorithm/dkpir/sender_dispatcher.cc
  • Implemented the DkPir sender dispatcher, handling OPRF requests and queries.
• psi/algorithm/dkpir/sender_dispatcher.h
  • Defined the DkPir sender dispatcher class.
• psi/apps/psi_launcher/BUILD.bazel
  • Added //psi/algorithm/dkpir:entry as a dependency to psi_launcher.
• psi/apps/psi_launcher/launch.cc
  • Added RunDkPir functions to handle DkPir sender and receiver configurations.
• psi/apps/psi_launcher/launch.h
  • Added function declarations for RunDkPir.
• psi/proto/entry.proto
  • Added DkPirSenderConfig and DkPirReceiverConfig to the LaunchConfig message.
• psi/proto/pir.proto
  • Added DkPirSenderConfig and DkPirReceiverConfig messages, and imported psi/proto/psi.proto.
• psi/utils/BUILD.bazel
  • Added csv_converter library and its test.
• psi/utils/csv_converter.cc
  • Implemented the ApsiCsvConverter class for converting CSV files.
• psi/utils/csv_converter.h
  • Defined the ApsiCsvConverter class.
• psi/utils/csv_converter_test.cc
  • Implemented tests for the ApsiCsvConverter class.

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Trivia time!

What does the acronym PIR stand for in the context of Private Information Retrieval?

Click here for the answer

PIR stands for Private Information Retrieval.

Footnotes

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[gemini-code-assist]

Code Review

The pull request introduces a new feature for Duplicate Key PIR (DkPir), including necessary code and configuration files. The changes seem well-structured, but there are a few points that need attention to ensure correctness and maintainability.

Summary of Findings

• Missing License Information: The MODULE.bazel file lacks license information for the newly added dependency 'heu'. This should be added to comply with licensing requirements.
• Potential Data Leakage: The current implementation of the DkPir scheme relies on the assumption that all client queries are present in the server's database. If this assumption is not met, the row count verification may fail, potentially leaking information about the client's query.
• Lack of Input Validation: The code does not appear to have sufficient input validation, especially for file paths and configurations. This could lead to unexpected behavior or security vulnerabilities.

Merge Readiness

The pull request introduces a significant new feature, but there are several issues that need to be addressed before merging. Specifically, the missing license information, potential data leakage, and lack of input validation should be resolved. I am unable to approve this pull request, and recommend that it not be merged until these issues are addressed.

[yunbo99]

I have read the CLA Document and I hereby sign the CLA

[qxzhou1010]

按照之前的Review结果均做了修改，算法Review这边无问题，代码本身方面我这边也暂未发现问题。请工程同学再DoubleCheck一下。

[qxzhou1010]

LGTM

[huocun-ant]

LGTM