Tag Archives: crowdsourcing

New Techniques in Fake Reviews

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2017/09/new_techniques_.html

Research paper: “Automated Crowdturfing Attacks and Defenses in Online Review Systems.”

Abstract: Malicious crowdsourcing forums are gaining traction as sources of spreading misinformation online, but are limited by the costs of hiring and managing human workers. In this paper, we identify a new class of attacks that leverage deep learning language models (Recurrent Neural Networks or RNNs) to automate the generation of fake online reviews for products and services. Not only are these attacks cheap and therefore more scalable, but they can control rate of content output to eliminate the signature burstiness that makes crowdsourced campaigns easy to detect.

Using Yelp reviews as an example platform, we show how a two phased review generation and customization attack can produce reviews that are indistinguishable by state-of-the-art statistical detectors. We conduct a survey-based user study to show these reviews not only evade human detection, but also score high on “usefulness” metrics by users. Finally, we develop novel automated defenses against these attacks, by leveraging the lossy transformation introduced by the RNN training and generation cycle. We consider countermeasures against our mechanisms, show that they produce unattractive cost-benefit tradeoffs for attackers, and that they can be further curtailed by simple constraints imposed by online service providers.

Crowdsourcing a Database of Hotel Rooms

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2016/06/crowdsourcing_a.html

There’s an app that allows people to submit photographs of hotel rooms around the world into a centralized database. The idea is that photographs of victims of human trafficking are often taken in hotel rooms, and the database will help law enforcement find the traffickers.

I can’t speak to the efficacy of the database, but it’s an interesting crowdsourced approach to the problem.

Waze Data Poisoning

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2016/06/wayz_data_poiso.html

People who don’t want Waze routing cars through their neighborhoods are feeding it false data.

It was here that Connor learned that some Waze warriors had launched concerted campaigns to fool the app. Neighbors filed false reports of blockages, sometimes with multiple users reporting the same issue to boost their credibility. But Waze was way ahead of them.

It’s not possible to fool the system for long, according to Waze officials. For one thing, the system knows if you’re not actually in motion. More important, it constantly self-corrects, based on data from other drivers.

“The nature of crowdsourcing is that if you put in a fake accident, the next 10 people are going to report that it’s not there,” said Julie Mossler, Waze’s head of communications. The company will suspend users they suspect of “tampering with the map,” she said.