Edward Snowden's disclosures (20.05.2023) shed light on the fact that the current level of surveillance in modern societies is incompatible with human rights. Many people, especially city dwellers, have a hard time going about their daily lives without falling under the gaze of public surveillance cameras in streets, public transport, buildings and public spaces. Cameras are everywhere including drones or other devices. With surveillance technology becoming more sophisticated, many of us must come to terms with the unsettling truth that maintaining our private life will become harder and harder. Even if the intention is to keep us safe, public surveillance can be harmful to society: there is indeed proof that the need for national security often trespasses individual privacy. Maintaining a balance between the two has been a very challenging task. It's essential to find a balance that respects both individual privacy and the need for security in a democratic society. In democratic countries, there is an expectation that government actions should be transparent, accountable, and subject to checks and balances. While security concerns are valid, the use of invasive surveillance technology should be subject to clear legal frameworks, oversight, and public debate.

Many people and organizations argue that safeguards should be in place to prevent the misuse of surveillance technologies and protect individuals' privacy rights. Concerns about potential abuse of power, mass surveillance, and the erosion of civil liberties have led to discussions about the need for robust legal and ethical frameworks governing surveillance practices. However, trying to protect citizens’ privacy just by establishing legal frameworks will not solve the problem. The reason is pretty clear and is known from the ancient times: Who will guard the guardians?

However, advancements in technology (cryptography, hardware and computational power) can help us build privacy-respecting surveillance systems. Keeping in mind that encryption is the best option for standing up against surveillance of any kind, creating camera programs that respect the democratic nature of societies is closer than ever.

Cryptography is the art and science of keeping information secure from unintended audiences. In other words, cryptography allows humans to keep their secrets safe. The fundamental concept behind protecting one's secrets (in this case data), is rather straightforward: Consider a scenario where you wish to send me a message through email. Naturally, this message is considered private information meant for only the two of us – the sender (you) and the recipient (me). You will employ your personal email account to send me this message. To do so, you will need to log in to your email account. Furthermore, for me to read your message, I will need to log in to my personal email account. This process entails the use of unique secrets, which are our passwords granting access to our respective email accounts. Assuming that only you have knowledge of your email password and only I possess knowledge of my email password, no one else can access the message you have sent me. Cryptography functions in a similar manner. To safeguard a message, we encrypt it with a specific password, known as a cryptographic key, rendering the message indecipherable to unauthorized individuals.

Keeping in mind that encryption is the best option for standing up against surveillance of any kind, time has come for the implementation of camera programs that respect the democratic nature of societies. At Tampere University we have been working on designing protocols that will run on cameras and will ensure that all sensitive information in a video will be always encrypted (e.g. faces). More precisely, every time that a camera is recording a video, an algorithm capable of identifying objects is running in the background. Then, each object is encrypted with a unique key. Thus, all sensitive information is kept secret.

Lets consider two examples:

• Helen is a 52 years old professor of history at the University of Athens. Helen, leaves her flat at Σπ. Μερκούρη 28 street, every day around 08.30. Then, she takes her bicycle and follows the same root to her office at the University. At the end of the day, she follows the same root to return back home (around 20.00). Imagine having cameras distributed in several parts of Helen’s route. Then, an authority who has access to those videos, will be able to know that a female in her 50s who leaves at Σπ. Μερκούρη 28, probably works at the University and she likes cycling. In addition to that, having access to all these face recognition algorithms, it wouldn’t be that tough to get access to more personal data for that female person who lives at Σπ. Μερκούρη 28 (e.g. name, surname, date of birth, etc.). So, there is no doubt that for Helen – a person who has never convicted any crime – this is a direct breach of privacy.
• Now, consider a case where one day that Helen is coming back from the University, a stranger kicks her off her bike and steals her back. In some days, and after consulting the cameras installed in the streets, the police identified and arrested the suspect.

So, it seems that we are trapped in a paradox. On one hand we want the cameras to protect us but on the other hand we do not want the cameras to record our daily lives. Fortunately, with the rapid development of science and technology a realistic solution seems to be quite close. More precisely, we are currently working on implementing protocols that will, by default, encrypt all possible sensitive information in a video and if and only if there has been identified an illegal action, an authority will be able to decrypt only the part of information needed to identify the suspect. So, in our second example, a legitimate authority will be given access to decrypt only the face of the person who stole Helen and nothing else, thus, respecting the privacy of all other citizens in the video.

Realizing such a promising technology, we hope governments will get the necessary help that will allow them to fulfil their responsibility to citizens, while answering the call for national security. After all, privacy is not just a regulation that authorities must abide by, but a fundamental human right that requires safeguarding.