protección de datos

As organisations seek to harness the potential of data to make decisions, innovate and improve their services, a fundamental challenge arises: how can data collection and use be balanced with respect for privacy? PET technologies attempt to address this challenge. In this post, we will explore what they are and how they work.

What are PET technologies?

PET technologies are a set of technical measures that use various approaches to privacy protection. The acronym PET stands for "Privacy Enhancing Technologies" which can be translated as "privacy enhancing technologies".

According to the European Union Agency for Cibersecurity this type of system protects privacy by:

• The deletion or reduction of personal data.
• Avoiding unnecessary and/or unwanted processing of personal data.

All this, without losing the functionality of the information system. In other words, they make it possible to use data that would otherwise remain unexploited, as they limit the risks of disclosure of personal or protected data, in compliance with current legislation.

Relationship between utility and privacy in protected data

To understand the importance of PET technologies, it is necessary to address the relationship between data utility and data privacy. The protection of personal data always entails a loss of usefulness, either because it limits the use of the data or because it involves subjecting them to so many transformations to avoid identification that it perverts the results. The following graph shows how the higher the privacy, the lower the usefulness of the data.

Figure 1. Relationship between utility and privacy in protected data. Source: "Introduction to PET technologies", Directorate-General for Data, June 2024.

PET techniques allow a more favourable privacy-utility trade-off to be achieved. However, it should be borne in mind that there will always be some limitation of usability when exploiting protected data.

Figure 2. Relationship between utility and privacy in PET and non-PET protected data. Source: "Introduction to PET technologies", Directorate-General for Data, June 2024.

Most popular PET techniques

In order to increase usability and to be able to exploit protected data while limiting risks, a number of PET techniques need to be applied. The following diagram shows some of the main ones:

Figure 3. Overview of PET techniques. Source: "Introduction to PET technologies", Directorate-General for Data, June 2024.

As we will see below, these techniques address different phases of the data lifecycle.

Before data mining: anonymisation

Anonymisation is the transformation of private data sets so that no individual can be identified. Thus, the General Data Protection Regulation (GDPR) no longer applies to them.

It is important to ensure that anonymisation has been done effectively, avoiding risks that allow re-identification through techniques such as linkage (identification of an individual by cross-referencing data), inference (deduction of additional attributes in a dataset), singularisation (identification of individuals from the values of a record) or compounding (cumulative loss of privacy due to repeated application of treatments). For this purpose, it is advisable to combine several techniques, which can be grouped into three main families:

• Randomisation: involves modifying the original data by introducing an element of chance. This is achieved by adding noise or random variations to the data, so that general patterns and trends are preserved, but identification of individuals is made more difficult.

• Generalisation: is the replacement or hiding of specific values in a data set with broader or less precise values. For example, instead of recording the exact age of a person, a range of ages (such as 35-44 years) could be used.

• Deletion: implies the complete removal of certain data from the set, especially those that can identify a person directly. This is the case for names, addresses, identification numbers, etc.

You can learn more about these three general approaches and the various techniques involved in the practical guide "Introduction to data anonymisation: techniques and practical cases". We also recommend reading the article Common misunderstandings in data anonymisation.

Data protection in use

This section deals with techniques that safeguard data privacy during the implementation of operational processing.

• Homomomorphic encryption: is a cryptographic technique which allows mathematical operations to be performed on encrypted data without first decrypting it. For example, a cipher will be homomorphic if it is true that, if two numbers are encrypted and a sum is performed in their encrypted form, the encrypted result, when decrypted, will be equal to the sum of the original numbers.

• Secure Multiparty Computation or SMPC: is an approach that allows multiple parties to collaborate to perform computations on private data without revealing their information to the other participants. In other words, it allows different entities to perform joint operations and obtain a common result, while maintaining the confidentiality of their individual data.

• Distributed learning: traditionally, machine learning models learn centrally, i.e., they require gathering all training data from multiple sources into a single dataset from which a central server builds the desired model. In el distributed learning, data is not concentrated in one place, but remains in different locations, devices or servers. Instead of moving large amounts of data to a central server for processing, distributed learning allows machine learning models to be trained at each of these locations, integrating and combining the partial results to obtain a final model.

• Trusted Execution Environments or TEE: trusted computing refers to a set of techniques and technologies that allow data to be processed securely within protected and certified hardware environments known as trusted computing environments.

• Synthetic data: is artificially generated data that mimics the characteristics and statistical patterns of real data without representing specific people or situations. They reproduce the relevant properties of real data, such as distribution, correlations and trends, but without information to identify specific individuals or cases. You can learn more about this type of data in the report Synthetic data:. What are they and what are they used for?

       3. Access, communication and storage

PET techniques do not only cover data mining. These also include procedures aimed at ensuring access to resources, communication between entities and data storage, while guaranteeing the confidentiality of the participants. Some examples are:

Access control techniques

• Private information retrieval or PIR: is a cryptographic technique that allows a user to query a database or server without the latter being able to know what information the user is looking for. That is, it ensures that the server does not know the content of the query, thus preserving the user's privacy.

• Privacy-Attribute Based Credentials or P-ABC: is an authentication technology that allows users to demonstrate certain personal attributes or characteristics (such as age of majority or citizenship) without revealing their identity. Instead of displaying all his personal data, the user presents only those attributes necessary to meet the authentication or authorisation requirements, thus maintaining his privacy.

• Zero-Knowledge Proof or ZKP: is a cryptographic method that allows one party to prove to another that it possesses certain information or knowledge (such as a password) without revealing the content of that knowledge itself. This concept is fundamental in the field of cryptography and information security, as it allows the verification of information without the need to expose sensitive data.

Communication techniques

• End to End Encryption or E2EE: This technique protects data while it is being transmitted between two or more devices, so that only authorised participants in the communication can access the information. Data is encrypted at the origin and remains encrypted all the way to the recipient. This means that, during the process, no intermediary individual or organisation (such as internet providers, application servers or cloud service providers) can access or decrypt the information. Once they reach their destination, the addressee is able to decrypt them again.

• Network Information Protection (Proxy & Onion Routing): a proxy is an intermediary server between a user's device and the connection destination on the Internet. When someone uses a proxy, their traffic is first directed to the proxy server, which then forwards the requests to the final destination, allowing content filtering or IP address change. The Onion Routing method protects internet traffic over a distributed network of nodes. When a user sends information using Onion Routing, their traffic is encrypted multiple times and sent through multiple nodes, or "layers" (hence the name "onion", meaning "onion").

Storage techniques

• Privacy Preserving Storage (PPS): its objective is to protect the confidentiality of data at rest and to inform data custodians of a possible security breach, using encryption techniques, controlled access, auditing and monitoring, etc.

These are just a few examples of PET technologies, but there are more families and subfamilies. Thanks to them, we have tools that allow us to extract value from data in a secure way, guaranteeing users' privacy. Data that can be of great use in many sectors, such as health, environmental care or the economy.

The emergence of artificial intelligence (AI), and ChatGPT in particular, has become one of the main topics of debate in recent months. This tool has even eclipsed other emerging technologies that had gained prominence in a wide range of fields (legal, economic, social and cultural).  This is the case, for example, of web 3.0, the metaverse, decentralised digital identity or NFTs and, in particular, cryptocurrencies.

There is an unquestionable direct relationship between this type of technology and the need for sufficient and appropriate data, and it is precisely this last qualitative dimension that justifies why open data is called upon to play a particularly important role. Although, at least for the time being, it is not possible to know how much open data provided by public sector entities is used by ChatGPT to train its model, there is no doubt that open data is a key to improving their performance.

Regulation on the use of data by AI

From a legal point of view, AI is arousing particular interest in terms of the guarantees that must be respected when it comes to its practical application. Thus, various initiatives are being promoted that seek to specifically regulate the conditions for its use, among which the proposal being processed by the European Union stands out, where data are the object of special attention.

At the state level, Law 15/2022, of 12 July, on equal treatment and non-discrimination, was approved a few months ago. This regulation requires public administrations to promote the implementation of mechanisms that include guarantees regarding the minimisation of bias, transparency and accountability, specifically with regard to the data used to train the algorithms used for decision-making.

There is a growing interest on the part of the autonomous communities in regulating the use of data by AI systems, in some cases reinforcing guarantees regarding transparency. Also, at the municipal level, protocols are being promoted for the implementation of AI in municipal services in which the guarantees applicable to the data, particularly from the perspective of their quality, are conceived as a priority requirement.

The possible collision with other rights and legal interests: the protection of personal data

Beyond regulatory initiatives, the use of data in this context has been the subject of particular attention as regards the legal conditions under which it is admissible. Thus, it may be the case that the data to be used are protected by third party rights that prevent - or at least hinder - their processing, such as intellectual property or, in particular, the protection of personal data. This concern is one of the main motivations for the European Union to promote the Data Governance Regulation, a regulation that proposes technical and organisational solutions that attempt to make the re-use of information compatible with respect for these legal rights.

Precisely, the possible collision with the right to the protection of personal data has motivated the main measures that have been adopted in Europe regarding the use of ChatGPT. In this regard, the Garante per la Protezione dei Dati Personali has ordered a precautionary measure to limit the processing of Italian citizens' data, the Spanish Data Protection Agency has initiated ex officio inspections of OpenAI as data controller and, with a supranational scope, the European Data Protection Supervisor (EDPB) has created a specific working group.

The impact of the regulation on open data and re-use

The Spanish regulation on open data and re-use of public sector information establishes some provisions that must be taken into account by IA systems. Thus, in general, re-use will be admissible if the data has been published without conditions or, in the event that conditions are set, when they comply with those established through licences or other legal instruments; although, when they are defined, the conditions must be objective, proportionate, non-discriminatory and justified by a public interest objective.

As regards the conditions for re-use of information provided by public sector bodies, the processing of such information is only allowed if the content is not altered and its meaning is not distorted, and the source of the data and the date of its most recent update must be mentioned.

On the other hand, high-value datasets are of particular interest for these AI systems characterised by the intense re-use of third-party content given the massive nature of the data processing they carry out and the immediacy of the requests for information made by users. Specifically, the conditions established by law for the provision of these high-value datasets by public bodies mean that there are very few limitations and also that their re-use is greatly facilitated by the fact that the data must be freely available, be susceptible to automated processing, be provided through APIs and be provided in the form of mass downloading, where appropriate.

In short, considering the particularities of this technology and, therefore, the very unique circumstances in which the data are processed, it seems appropriate that the licences and, in general, the conditions under which public entities allow their re-use be reviewed and, where appropriate, updated to meet the legal challenges that are beginning to arise.

Content prepared by Julián Valero, Professor at the University of Murcia and Coordinator of the "Innovation, Law and Technology" Research Group (iDerTec).

The contents and points of view reflected in this publication are the sole responsibility of the author.

The coming days will see the beginning of a season of sun, heat, beach and, in many cases, more free time, which makes this season a perfect opportunity to expand our training on a wide variety of subjects, among which data, a cross-cutting subject in different sectors, cannot be missing.

There are an increasing number of courses related to Big Data, science, analytics and even data journalism that we find in the summer offers of training centres. There is a growing interest in further training in these subjects due to the high demand for professional profiles with these skills.

Whether you are a student or a working professional, here are some examples of summer courses that may be of great interest to broaden your knowledge during these weeks:

Data science

The University of Castilla-La Mancha is offering the course "Data science: impact on society" on 22 and 23 June at the Albacete campus, where the new ways of acquiring and using data resulting from advances in technology and artificial intelligence will be discussed.

This summer, the University of Deusto will offer online training on "Data analysis and applied machine learning". This course, which will begin on 27 June, will teach you to master the main technologies for analysing and processing large amounts of data, as well as some techniques to increase the value of the data analysed, promoting optimal decision-making.

The University of Alicante focuses on artificial intelligence with the course "Introduction to Deep Learning" from 11 to 15 July 2022, in classroom mode. The course will begin by explaining basic concepts and the use of basic and advanced packages such as NumPy, Pandas, scikit-learn or tf.Keras, and then continue to delve deeper into neural networks.

The University of Alcalá de Henares will talk about "Introduction to financial data science with R" in an on-site course from 20 to 24 June. The aim of the course is twofold: to familiarise students with the use of the statistical language and to show some of the techniques linked to advanced statistical calculation, as well as its practical applications.

Open data

The Complutense University of Madrid offers, once again this year, its course “Big & Open Data. Analysis and programming with R and Python” from 4 to 22 July 2022 (mornings from 9:00 to 14:00, Monday to Friday). The course will cover the data life cycle, examples of Big Data use cases and ethics applied to the management of massive data, among other topics.

Geographic Information Systems

If you are passionate about geographic data, the University of Santiago is offering the course "Introduction to geographic information systems and cartography with the R environment" from 5 to 8 July 2022. In classroom format and with 29 teaching hours, it aims to introduce students to spatial analysis, visualisation and working with raster and vector files. The main geostatistical interpolation methods will be covered during the course.

The University of Alcalá de Henares, for its part, will give the course "Applications of GIS to Hydrology", from 6 to 8 July, also in classroom format. This is a practical course that covers everything from the different sources of hydro-meteorological data to carrying out evapotranspiration and runoff analyses and obtaining results.

Data journalism

El Institut de Formació Contínua – IL3 de la Universitat de Barcelona organizará del 4 al 7 de julio de 2022 el curso online en castellano “Bulos y periodismo de datos”. Esta formación de 8 horas de duración te aportará los conocimientos necesarios para comprender, identificar y combatir el fenómeno de la desinformación. Además, conocerás las herramientas esenciales que se utilizan en el periodismo de datos, la verificación de datos (fact-checking) políticos y la investigación basada en peticiones de transparencia.

Data protection

The Menéndez Pelayo International University will hold a course on "Strategies for data protection in the face of the challenges of the digital environment" on 4, 5 and 6 July. The programme is aimed at students related to the business world, the provision of digital services, public administrations, researchers and those interested in the subject. “Smart-cities and personal data processing” or “the European Data Protection Committee and the European initiatives of the digital package” will be just some of the topics to be addressed in this course.

Another of the training courses related to data protection that will be given over the coming months will be "Are our data really ours? Risks and guarantees of personal data protection in digital societies". The International University of Andalusia will be responsible for giving this course, which will be held in person in Seville from 29 August, and which will address the current situation of personal data protection within the framework of the European Union. Through this training you will discover the benefits and risks involved in the processing of our personal data.

In addition to this specific summer training, those users who wish to do so can also go to the large MOOC course platforms, such as Coursera, EDX or Udacity, which offer interesting courses on a continuous basis so that any student can start learning whenever they need to.

These are just a few examples of courses that are currently open for enrolment this summer, although the offer is very wide and varied. Moreover, it should be noted that the summer has not yet begun and new training courses related to the field of data could emerge in the coming weeks. If you know of any other course that might be of interest, do not hesitate to leave us a comment below or write to us at contacto@datos.gob.es.