The goal is to improve cybersecurity solutions for cloud computing
Researcher Jéferson Nobre (UFRGS) has been working on a relatively new research approach related to cybersecurity applied to cloud computing: confidential computing. As the researcher explains, even though much is known about the field of cybersecurity, there are several challenges that are specific to cloud computing. These challenges require looking beyond what is normally considered in security.
What’s new?
Cloud computing has become the invisible backbone of our digital lives. Text messages, artificial intelligence systems, apps—practically everything depends on this infrastructure. In this context, what are the main security gaps, and where are we most vulnerable?
Today, our devices—especially smartphones—lack the capacity to process everything locally. That’s why we constantly send data to the cloud, where it is processed and returned. And this creates vulnerability, as it’s not uncommon for cloud providers to leak information—even if unintentionally. This is an attack on confidentiality and privacy, which has been observed in many incidents in recent years, fueling growing concern about this vulnerability.
In information security, two fundamental concepts are confidentiality and privacy. Confidentiality is the responsibility of organizations or companies that are accountable for user privacy. That is, service providers must ensure that only they and the individuals to whom they grant access rights will access user information. Users, on the other hand, have the right to keep their information private.
The greatest vulnerability, therefore, lies in processing. Although there are mature solutions for data at rest and in transit, the processing phase remains a gap that confidential computing seeks to fill in order to extend security guarantees to the moment of processing.
The contribution of Confidential Computing
In this context, confidential computing aims to provide a set of techniques and architectures that enable workloads to be executed in isolated environments, with formal guarantees of confidentiality and integrity.
Confidential computing is based on the idea that it is possible to create, within the cloud, a secure environment in which data can be processed without compromising confidentiality. This is made possible through so-called Trusted Execution Environments (TEEs). This technology is hardware-based and works by creating, within the processor itself, an isolated and protected area. In this space, both the data and the code remain encrypted, preventing external access—including by the cloud provider.
In addition, this environment supports a mechanism called remote attestation, which allows for remote verification that the code being executed is exactly the one that was originally submitted and that it is running within a secure environment. This increases confidence in the processing of sensitive data in the cloud.
Anonymous Communication
The problem is that, even with these approaches, it is still possible to identify who generated a particular workload by analyzing the traffic. This type of vulnerability is associated with so-called metadata attacks—that is, information about the data itself, such as who sent it, the volume transmitted, the time, and the frequency of interactions. To mitigate this risk, anonymous communication has emerged, whose purpose is to decouple the data from the identity of the sender by separating this information.
Currently, there are already some standards in this area. One of the main ones is OHTTP (Oblivious HTTP), a variation of the HTTP protocol that introduces anonymity into data transmission. This model requires the presence of an intermediary element independent of the organization (relay resource) and a gateway, acting between the user and the trusted execution environment. This adds an extra layer of protection, making it difficult to correlate the transmitted data with its source.
The case of messaging systems
As a central case study, Nobre highlights the Meta Private Processing system, which uses Trusted Execution Environments (TEEs), remote attestation, and the Oblivious HTTP protocol to process WhatsApp messages via the cloud (the only possible option, since it is not possible to process the information using AI with the resources of each user’s smartphone) without the company accessing the content or metadata.
The idea is to generate conversation summaries using AI without the provider having access to the content, which would guarantee user privacy (currently ensured by end-to-end encryption).
The solution would be a confidential computing + anonymous computing pipeline, enabling AI processing in a way that preserves the privacy promises WhatsApp makes. In this solution, no component has simultaneous access to the user’s identity, the content, and the execution environment.
Nowadays, Meta has Meta AI, which is manually added to a conversation and has access only to what the user explicitly sends, not to the user’s entire inbox. This is a superficial control. In the case of Private Processing, the user’s entire inbox is processed, and the user must voluntarily enable this feature. Confidentiality is ensured by a set of technologies that include TEE and OHTTP. An intermediary company is responsible for decoupling the source and destination, and another company handles the audit—which presents a challenge, as this company must be independent and reputable. Additionally, another organization plays a role in configuring cryptographic keys. For the adoption of these technologies, ecosystem fragmentation is one of the major obstacles.
Additional challenge
The encrypted environment within the cloud comes at a high cost. The use of TEEs requires that the Large Language Model (LLM) be run entirely within this secure environment. In this context, it is not appropriate to use general models belonging to service providers, such as those from Meta, since this could imply the use of processed data for training purposes. Thus, processing must occur in isolation within the trusted environment, ensuring that the data is used exclusively for task execution and subsequently deleted without any retention.
How to address confidential computing and anonymous communication
Confidential computing is capable of bridging the gap between data protection at rest/in transit and in use, which represents a real advance but does not constitute a complete solution for cloud system security. The guarantees depend on the integrity of the hardware, firmware, supply chain, and attestation services. Trust is extended and redistributed. In this context, anonymous communication is complementary, protecting metadata that anonymous computing alone does not cover. Auditability and transparency are non-optional requirements, as independent audits and immutable logs are part of the trust model.
Watch Jéferson Nobre’s presentation
On April 16, 2026, researcher Jéferson Nobre presented a webinar titled “Security Analysis of Confidential Computing and Anonymous Communication,” providing examples and diagrams to help illustrate the topics discussed. Watch it on our YouTube channel