Introduction

PPLP: Privacy-Preserving Location Proximity

(面向位置保护的隐私距离计算与近邻检测)

Requirements

• seal-4.1
• toolchains: cmake, g++/clang++, python3
• termux(for android)

Build

Linux/WSL

git clone https://github.com/phanen/pplp.git
mkdir build && cd build
CC=clang CXX=clang++ cmake -S . -B build
CC=clang CXX=clang++ cmake --build build

tested on debian, ubuntu, arch

Android

Provide a hack way to run on Android. Check FAQ.

Windows

Non-interactive version only:

make pplp # after cmake

If you cannot build... you can try

• Generate Makefile using llvm-clang and mingw32-make
• Replace something in Makefile...

Usage

After build you will find the follow executable program in your directory:

• ./demo -- Local version to test the protocol
• ./server && ./client -- C/S version
• ./ts && ./tc -- Generate Benchmark in *.csv format.

To get manual of specific program, type:

./server --help

the manual

usage: ./server [options] ... 
options:
  -h, --host      ip of server (string [=127.0.0.1])
  -p, --port      port of server (unsigned short [=51022])
  -u, --xb        coordinate1 of server (unsigned long [=123456888])
  -v, --yb        coordinate2 of server (unsigned long [=132465777])
  -r, --radius    radius/thershold (unsigned long [=128])
  -?, --help      print this message

GPS support python3 ./src/get_pos.py will print cmdline flavor coordinate, integrate it in pplp by:

./build/server $(python3 ./src/get_pos.py)

To Do

• Add serialization for Bloom Filter
• Implementing C/S demo
• Hash function (on blind distance)
• Set parms of RNG (size of random number)
• Secure parms

FAQ

How to build seal

git clone https://github.com/microsoft/SEAL.git
cd SEAL
CC=clang CXX=clang++ cmake -S . -B build
CC=clang CXX=clang++ cmake --build build
sudo cmake --install build

Want to use other toolchains?

CC=clang CXX=clang++ cmake .. -G=...

How to deploy a server in LAN?

• Port mapping. (anyway, a host with public ip is necessary)
• e.g. Use frp. You may need add the following field.

  [common]
  tls_enable=true

How to build on android?

The following guide help build a vm in termux. Not sure if pplp can be directly built on termux

Modify sources.list

sed -i 's@^\(deb.*stable main\)$@#\1\ndeb https://mirrors.tuna.tsinghua.edu.cn/termux/apt/termux-main stable main@' $PREFIX/etc/apt/sources.list
apt update && apt upgrade

ssh on termux

pkg install openssh -y
/etc/ssh/sshd_config
cat "Port 8022" >> /etc/ssh/sshd_config # banned 1~1024 (no root...)
sshd # For access to GPS of android (no root...)

install ubuntu on termux (22.04 currently)

pkg install proot proot-distro -y 
proot-distro install ubuntu
proot-distro login ubuntu
apt install python3 openssh-server -y
# nano /etc/ssh/sshd_config
cat "Port 9022" >> /etc/ssh/sshd_config 
cat "PermitRootLogin yes" >> /etc/ssh/sshd_config 
/usr/sbin/sshd

build pplp, then run

./client -h <ip of server> -p <port of server> $(ssh user127.0.0.1 -p 8022 "termux-location" | python3 get_pos_mobile.py)

When open sshd, you might need to mkdir -p <something>.