New Location Proof System Enhances Citizen Journalism

In today's digital world, many online services depend on the locations that users say they are at. This is common with smartphones where users can share their location. However, sometimes people provide false locations, which can cause problems. To address this, researchers have created systems called location proof services (LPSs). These systems help verify a device’s location by checking it against other devices nearby or trusted networks.

This article discusses a new LPS that improves upon earlier systems in two main ways. First, instead of proving a device was at an exact location, this system proves a device was within a certain distance of that location. These proofs, called region proofs, are valuable because they require less strict behavior from devices reporting their locations. For instance, knowing how far someone is from a significant event can help assess the relevance of their reports. If someone is near an earthquake, their report becomes more relevant than someone much farther away.

The second innovation in this new system is its ability to prevent Collusion Attacks. A collusion attack is when a group of devices, controlled by an attacker, confirm each other's fake locations. This new system does not require extra infrastructure to protect against these attacks, even when the attacker creates many virtual devices at any place without any cost.

#The Role of Citizen Journalism

Today, anyone with a smartphone can record events as they happen and share them online. This ability gives rise to citizen journalism, where ordinary people can report news in real-time without traditional media's filters. Social media platforms, such as Instagram and Facebook, have become vital in sharing this unedited information.

Citizen journalism is particularly important during unexpected events like natural disasters, protests, or other crises. For example, during the Iranian protests in 2009 or the Egyptian uprising in 2011, individuals shared vital information that bypassed government control. Similarly, during the London bombings in 2005, citizen reports, in the form of photos and videos, added significant value to traditional news coverage.

However, one major downside of citizen journalism is that it does not always meet the same standards as traditional media. This can lead to reports varying in quality and reliability, sometimes even spreading misinformation. Therefore, verifying the quality and truthfulness of these citizen reports is crucial, which leads to the need for effective systems to validate the locations of these reports.

#Importance of Location Verification

When a citizen reports an event, confirming their location at that time is essential for the report's credibility. If someone was indeed near the incident, they are more likely to provide an accurate account of what happened. This is especially relevant during unpredictable events like earthquakes or attacks, where professional journalists may not be present initially. Knowing that a citizen was physically close to an event provides authenticity to their report and any related media such as photos or videos.

If an individual wishes to submit a report about a significant event, they must have been near the location at the right time, making it challenging for those looking to mislead.

#Requirements for Location Proof Services

Several existing LPSs aim to provide evidence of a device's location. However, they do not meet the specific needs of citizen journalism. Firstly, an effective LPS should generate location proof for any time and place a user visited. Secondly, it must withstand collusion attacks where many fake devices attempt to create misleading proofs.

Many current LPSs use trusted Wi-Fi stations to generate proofs, but this is often impractical at event locations. Other systems require exact radio contacts with nearby devices at the precise time and location of interest. If such contacts don’t exist, they cannot provide any proof. Even those with partial defenses against collusion attacks struggle against larger-scale collusions involving virtual devices.

#New Location Proof System Design

The new LPS introduces region proofs, allowing for more flexibility in how it verifies locations. These region proofs can be established with less rigid requirements on devices reporting their behavior. In many real-life situations, especially during unplanned events, knowing that someone is within a certain distance from a location is much more practical than knowing their exact location.

To protect against collusion attacks, the new system uses a familiarity-trust-based approach. Each device regularly uploads its location history alongside data from encounters with nearby devices. This history allows the LPS to construct a plausible region where a device could have been at a specific time based on these interactions.

Devices involved in the LPS employ Bluetooth Low Energy (BLE) technology, which offers efficient data sharing without significant battery consumption. This design allows devices to report their locations and interactions frequently.

#How the New System Works

The LPS begins by gathering location histories from various devices and establishes encounters based on regular BLE interactions. Each device uploads information about its location and any BLE advertisements it receives from other devices.

The system then assesses which of these encounters are trustworthy. By focusing on the relationships between devices and the trustworthiness of their interactions, the system is able to identify suspicious devices. The core idea is that while an attacker can create numerous virtual devices, their connections with real devices will be limited, thus making them easier to identify.

#Preventing Collusion Attacks

The system specifically focuses on retroactive collusion attacks, where attackers try to prove that their devices were at a specific location after the fact, without prior knowledge of where they would need a proof. This scenario is particularly relevant for citizen journalism, where unexpected events cannot be predicted.

In such cases, colluding devices report false locations and attempt to establish encounters that never occurred. The new LPS uses a trust calculation method that evaluates device interactions to flag these suspicious activities. By understanding how devices behave relative to trusted devices, the system can weed out the virtual devices trying to manipulate the proof system.

#Experimental Results

The new LPS was evaluated using simulated datasets that mimic real-world interactions and BLE communications. These experiments aimed to measure how well the system could generate credible location proofs and identify fake devices in various scenarios.

Results showed that the system could effectively provide location proofs with a good degree of precision, even when a small number of honest devices were present. The trust algorithm proved proficient at distinguishing between real and fictitious devices while maintaining a high rate of accuracy for honest devices.

#Conclusion

In summary, the new location proof service offers vital improvements over existing systems by providing region proofs that require less strict reporting behavior from devices. It also features strong defenses against collusion attacks, making it particularly suitable for applications in citizen journalism. With increasing reliance on citizen reports for real-time news, having a robust system to verify these reports can greatly enhance the quality and authenticity of information shared online. By employing trust calculations and efficient data collection methods, this LPS stands to significantly improve how location data is verified in a world where misinformation can spread rapidly.