Security,Privacy and Safety

Introduction

This section outlines security, privacy and safety concerns that keep you awake when applying machine learning for real business use.

The complexity of ML technologies has fuelled fears that machine learning applications causes harm in unforeseen circumstances, or that they are manipulated to act in harmful ways. Think of a self driving car with its own ethics or algorithms that make prediction based on your personal data that really scare you. E.g. Predicting what diseases hit you based on data from your grocery store.

As with any technology: Technology is never neutral. You have to think before starting what values you implicitly use to design your new technology. All technology can and will be misused. But it is up to the designers to think of the risks when technology will be misused. On purpose or by accident.

Machine learning systems should be operated reliably, safely and consistently. Not only under normal circumstances but also in unexpected conditions or when they are under attack for misuse.

Machine learning software differs from traditional software because:

  • The outcome is not easily predictable.

  • The used trained models are a black box, with very few options for transparency.

  • Logical reasoning (or cause and effect) is not present. Predictions are made based on statistical number crunching complex algorithms which are non linear.

  • Both Non IT people and trained IT people have a hard time figuring out machine learning systems, due to the new paradigms in use.

What makes security and safety more than normal aspects for machine learning driven applications is that by design neural networks are not designed to to make the inner workings easy to understand for humans and quality and risk managers.

Without a solid background in mathematics and software engineering evaluating the correct working of most machine learning application is impossible for security researchers and safety auditors.

However more and more people dependent on the correct outcome of decisions made by machine learning software. So we should ask some critical questions:

  • Is the system making any mistakes?

  • How do you know what alternatives were considered?

  • What is the risk of trusting the outcome blind?

Understanding how output produced by machine learning software is created will make more people comfortable with self-driving cars and other safety critical systems that are machine learning enabled. In the end systems that can kill you must be secure and safe to use. So how do we get the process and trust chain to a level that we are not longer depended of:

  • Software bugs

  • Machine learning experts

  • Auditors

  • A proprietary certification process that end with a stamp (if paid enough)

From other sectors, like finance or oil industry we know that there is no simple solution. However regarding the risks involved only FOSS machine learning applications have the right elements needed to start working on processes that give enough trust to use machine learning system for society at large.

To reduce risks for machine learning systems needed is:

  • Transparency: ML systems should be understandable. However they will never be. Computer science is a complex field. Only a fraction of the people are able to grasp the complete working of software and hardware in modern computer systems. So we need to find ways to manage and reduce risks in order to trust systems enabled by ML software. Transparency can be realized by using FOSS software (for everything). But beware that real trust requires that anyone with the needed expertise should be able to rebuild the software and retrain also the created machine learning model using the same training input. In open science for machine learning this is now becoming the new de-facto standard for scientific research.

  • Reproducible. All data and created models must be available so other research can verify the working independently.

Trusts means no security by obscurity. So open research, open science, open software and open business innovation principles should be used when machine learning applications are developed and deployed.

Security

Using machine learning technology gives some serious new threads. More and more new ways for exploiting the technology are published. IT security is proven to be hard and complex to control and manage. But machine learning technology makes the problem of IT security even worse. This is due to the fact that the special created machine learning exploits are very hard to determine.

Machine learning challenges many current security measurements. This because machine learning software:

  • Lowers the cost of applying current known attacks on all devices which depend on software. So almost all modern technology devices.

  • Machine learning software enables the easy creation of new threats and vulnerabilities on existing systems. E.g. you can take the CVE security vulnerability database (https://www.cvedetails.com/) and train a machine learning model how to create attack on the published omissions.

  • When machine learning software will be in hospitals, traffic control systems, chemical fabrics and IoT devices machine learning gives easier options to create a complete new attack surface as with traditional software.

Security aspects for machine learning accounts for the application where machine learning is used, but also for the developed algorithms self. So machine learning security aspects are divided into the following categories:

  • Machine learning attacks aimed to fool the developed machine learning systems. Since machine learning is often a ‘black-box’ these attacks are very hard to determine.

  • System attacks special for machine learning systems. Machine learning offers new opportunities to break existing traditional software systems.

  • Machine learning usage threats. The outcome of many machine learning systems is far from correct. If you base decisions or trust on machine learning applications you can make serious mistakes. This accounts e.g. for self driving vehicles, health care systems and surveillance systems. Machine learning systems are known for producing racially biased results often caused by using biased data sets. Think about problematic forms of “profiling” based on surveillance cameras with face detection.

  • Machine learning hosting and infrastructure security aspects. This category is not special for machine learning but is relevant for all IT systems. Protecting ‘normal’ software solutions was already a known challenge. But inspecting and protecting machine learning systems require besides already deep knowledge of cyber security also knowledge of nature of machine learning systems. And remember: Machine learning systems are not traditional software systems. A machine learning systems is a complete other paradigm that requires new knowledge of building a thread model to take measurements to reduce security risks. When manipulated training data is used when training your machine learning model it make results horrible and can be dangerous.

So key threads for machine learning system can be seen as:

  • Attacks which compromise confidentiality

  • Attacks which compromise integrity by manipulation of input.

  • ‘Traditional’ attacks that have impact on availability.

Attack vectors for machine learning systems can be categorized in:

  • Input manipulation

  • Data manipulation

  • Model manipulation

  • Input extraction

  • Data extraction

  • Model extraction

  • Environmental attacks (so the IT system used for hosting the machine learning algorithms and data)

Taxonomy and terminology of machine learning is not yet fully standardized. The US NIST publication 8269 (The National Institute of Standards and Technology) a taxonomy and terminology of Adversarial Machine Learning is proposed. See https://csrc.nist.gov/publications/detail/nistir/8269/draft. Adversarial Machine Learning (AML)introduces additional security challenges in training and testing (inference) phases of system operations. AML is concerned with the design of ML algorithms that can resist security challenges, the study of the capabilities of attackers, and the understanding of attack consequences.

Top Machine Learning Security Risks

  • Adversarial attacks: The basic idea is to fool a machine learning system by providing malicious input that cause the system to make a false prediction or categorization.

  • Data poisoning: Machine learning systems learn directly from data. Intentionally manipulated data can compromise the machine learning application. If you want to make yourself e.g. invisible for face recognition you can create or buy special clothes.

  • Data confidentiality: An unique challenge in machine learning is protecting confidential data.

  • Data trustworthiness: Data integrity is essential. Are the data suitable and of high enough quality to support machine learning? Are e.g. sensors to capture data reliable? How is data integrity preserved? Understanding machine learning data sources, both during training and during execution, is of critical importance.

  • Overfitting Attacks: Overfitting means the model fits the parameters too closely with regard to the particular observations in the training dataset, but does not generalize well to new data. Most of the time the model is too complex for the given training data. Overfit models are particularly easy to attack.

  • Output integrity. If an attacker can interpose between a machine learning system and produced output, a direct attack on output is possible. The inscrutability of machine learning models (so not really understanding how they work) may make an output integrity attack easy and hard to spot.

Some examples of machine learning exploits:

  • Google’s Cloud Computing service can be tricked into seeing things that are not there. In one test it perceived a rifle as a helicopter.

  • Fake videos made with help from machine learning software are spreading online, and the law can’t do much about it. E.g. videos with speeches given by political leaders created by machine learning software are created and spread online. E.g. a video where some president declares a war to another country is of course very dangerous. Even more dangerous is the fact that the fake machine learning created videos are very hard to diagnose as machine learning creations. This since besides machine learning a lot of common Hollywood special effects are also used to make it hard to distinguish real videos from fake video’s. Creating online fake porn video sites were you can use a photo of a celebrity or someone you do not like, is nowadays only just three mouse clicks away. And the reality is that you can do very little against these kinds of damaging threads. Even from a legal point of view.

Users and especially developers of machine learning applications must be more paranoid from a security point of view. But unfortunately security cost a lot of effort and money and a lot of special expertise is needed to minimize the risks.

Privacy

Machine learning raises serious privacy concerns since machine learning is using massive amounts of data that contain often personal information.

It is a common believe that personal information is needed for experimenting with machine learning before you can create good and meaningful applications. E.g. for health applications, travel applications, eCommerce and of course marketing applications. Machine learning models are often loaded with massive amounts of personal data for training and to make in the end good meaningful predictions.

The belief that personal data is needed for machine learning creates a tension between developers and privacy aware consumers. Developers want the ability to create innovative new products and services and need to experiment, while consumers and GDPR regulators are concerned for the privacy risks involved.

The applicability of machine learning models is hindered in settings where the risk of data leakage raises serious privacy concerns. Examples of such applications include scenar-ios where clients hold sensitive private information, e.g., medical records, financial data, or location.

It is commonly believed that individuals must provide a copy of their personal information in order for AI to train or predict over it. This belief creates a tension between developers and consumers. Developers want the ability to create innovative products and services, while consumers want to avoid sending developers a copy of their data.

Machine learning models can be trained in environments that are not secure on data it never has access to. Secure machine learning that works on anonymized data sets is still an obscure and unpaved path. But some companies and organizations are already working on creating deep learning technology that works on encrypted data. Using encryption on data to train machine learning models raises the complexity in various ways. It is already hard or impossible to understand the inner working of the ‘black-box’ machine learning models. Using advanced data encryption will require even more knowledge and competences for all engineers involved when developing machine learning applications.

In the EU the use of personal data is protected by law in all countries by a single law. The EU General Data Protection Regulation (GDPR). This GDPR does not prohibit the use of machine learning. But when you use personal data you will have a severe challenge to explain to DPOs (Data Protection Officers) and consumers what you actually do with the data and how you comply with the GDPR.

Machine learning systems must be data responsible. They should use only what they need and delete it when it is no longer needed (“data minimization”). They should encrypt data in transit and at rest, and restrict access to authorized persons (“access control”). Machine learning systems should only collect, use, share and store data in accordance with privacy and personal data laws and best practices. Since FOSS machine learning needs full transparency and reproducibility using private data should be avoided if possible.

When you apply machine learning for your business application you should consider the following questions:

  • In what way will your customers be happy with their data usage for their and your benefit?

  • Do you really have a clear and good overview of all GDPR implications when using personal data in your machine learning model? What happens if you invite other companies to use your model?

  • What are the ethical concerns when using massive amounts of data of your customers to develop new products? Is the way you use the data to train your model congruent with you business vision and moral?

  • What are the privacy risks involved for your machine learning development chain and application?

Since security and privacy is complex to apply, frameworks are being developed to make this challenge easier. E.g. Tensorflow Encrypted aims to make privacy-preserving deep learning simple and approachable, without requiring expertise in cryptography, distributed systems, or high-performance computing. And PySyft is a Python library for secure, private Deep Learning. More on both frameworks can be found in the section on open ML software.

Safety

Machine learning is a powerful tool for businesses. But it can also lead to unintended and dangerous consequences for users of systems powered by machine learning software. The cause of safety issues is linked to the people and data that train and deploy the machine learning software and systems. Everyone involved in creating machine learning based systems should be aware of possible safety risks come when using machine learning technology.

Safety is a multifaceted area of research, with many sub-questions in areas such as reward learning, robustness, and interpretability.

A machine learning driven system can currently only be as good as the data it is given to work with. However you almost can never traceback to the data that was used to train and develop the system. This makes that the safety aspect should be kept in mind when dealing with security aspects for systems that deal direct or indirect with humans.

To avoid dangerous bias or incorrect actions from systems, you should develop machine learning system in the open and make the everything reproducible from the start.

However safety risks will always be there: It is impossible to cover all perspectives and variables for a machine learning system in development before it is released. And the nature of machine learning systems means that the outcome of machine learning is never perfect. Risks will always be present. So not all use cases possible for machine learning are acceptable from an ethical point of view.

The following activities will reduce safety risks and increase reliability of machine learning systems:

  • Systematic evaluation: So evaluate the data and models used to train and operate machine learning based products and services.

  • Create processes for solid documenting and auditing operations.

  • Involve domain experts. Involvement of domain experts in the design process and operation of machine learning systems. Also involve real people in advance who are in the end targeted by outcomes of ml systems especially when decisions about people are made using machine learning applications.

  • Evaluation of when and how a machine learning system should seek human input during critical situations, and how a system controlled by a human in a manner that is meaningful and intelligible.

  • A robust feedback mechanism so that users can report issues they experience.