DKIM (DomainKeys Identified Mail) is a security mechanism that uses a cryptographic digital signature to certify the authenticity of an email. This standard ensures that the message was actually dispatched by the declared domain and that it has not been modified during its journey to the recipient.
To operate, the system requires a pair of keys: a public key, which is registered in the domain's DNS, and a private key, used to sign the header of each transmission. When the destination server receives the content, it uses the public key to verify the signature, thus confirming the integrity of the email.
This technology protects brands and institutions against phishing threats and enhances the sender's credibility with service providers. By preventing legitimate communications from being classified as spam, the protocol ensures a safer and more reliable flow of information for important messages.
DKIM applies an encrypted digital signature stamp to emails, informing receiving servers that the message is genuine and unaltered. This validation protects the identity of a company or organization, hindering schemes like spoofing and phishing, as it prevents fraudsters from impersonating the legitimate domain.
Additionally, this method improves message delivery and prevents valid sends from ending up in the junk folder. In collaboration with SPF and DMARC, the technology helps strengthen the sender's reputation and optimize email traffic.
The operation of DKIM begins with generating a pair of cryptographic keys in the email server settings. The public key must be entered into a specific DKIM record in the domain's DNS so that recipients can consult it.
At the time of sending, the server creates a unique security code based on the content of each email. This information is then encrypted using the private key and attached to the message header as the DKIM signature. Upon arrival, the receiving server queries the sender's DNS to obtain the corresponding public key. Using this key, it decodes the header and recalculates the security code to compare the data.
If the codes match, the system confirms that the message was not altered in transit and allows it entry. This procedure validates the authenticity of the send, helping the message bypass spam filters and gain the trust of security systems.
Manual configuration of DKIM is not necessary for personal and free accounts, such as common Gmail accounts, as the providers themselves perform the authentication automatically. However, the feature is mandatory for corporate emails that use a proprietary domain in services like Google Workspace or Outlook. The process involves creating a public key in the provider's panel and adding it to the website's DNS settings.
The main benefits of DKIM include integrity assurance, where the signature acts as an inviolable seal, ensuring that no content or link has been tampered with. It also blocks forgeries, as scammers without access to the private key cannot create valid signatures, preventing phishing attacks.
Authenticated messages improve their reputation with security filters, facilitating their passage to the reader and reducing the chance of going to spam. Furthermore, DKIM protection remains valid even when the email is forwarded by third parties. Finally, it serves as a fundamental basis for more advanced security policies, such as DMARC.
The limitations of DKIM include the technical complexity in key generation and DNS record updates, which can be laborious in corporate environments with multiple systems. Any automatic alteration in transit, such as footers inserted by antivirus software, can invalidate the signature, making a legitimate email appear suspicious.
It is important to note that the protocol only validates the message, without determining a specific action in case of failure; for that, it depends on DMARC support. Moreover, DKIM does not prevent replay attacks, allowing a criminal to resend a previously signed valid email. Lastly, it does not guarantee the sender's reliability, only the message's integrity.
While DKIM seals each email with a unique cryptographic signature verified via a public key in the DNS, DMARC establishes strict guidelines, such as rejecting or quarantining messages that fail SPF or DKIM checks. DMARC integrates these protocols into the visible sender address, protecting the inbox. SPF, on the other hand, functions as a public list in the DNS, specifying which servers and IPs are authorized to send emails on behalf of the domain, thereby blocking sends from unauthorized sources.
Unlike encryption, which scrambles all content to ensure absolute confidentiality, DKIM is an authentication method that acts as a digital seal in the header, proving the origin and integrity of the message, but without hiding the text.
Samsung is scheduled to hold the Galaxy Unpacked 2026 event on Wednesday, July 22nd, starting at 10 am. At this event, the company is expected to reveal several innovative products, with a special focus on the Galaxy Z Fold 8, which will have a format described as a 'passport'.
Rumors suggest that the Galaxy Z Fold 8 will have closed dimensions of 129 x 82.2 x 9.8 mm and an expanded screen of 161.4 mm in width. This model would be the first from Samsung with a 4:3 aspect ratio, resembling a passport booklet. Its specifications include two rear cameras up to 50 MP, a 4,800 mAh battery, and support for 45-watt charging.
The line is also expected to introduce the Galaxy Z Flip 8, which is anticipated to bring few changes compared to the previous model. Additionally, there will be the introduction of two new Galaxy Watch devices and a smart glasses equipped with artificial intelligence.
There are speculations about a change in the line's nomenclature, where the new foldable would be named Galaxy Fold 8, and the successor to the Z Fold 7 would be called Z Fold 8 Ultra. Although there is this name change, rumors suggest that the Ultra device will not have a significant advancement in terms of functionality.
The Galaxy Z Fold 8 Ultra, which would be the most robust model, would maintain the three cameras up to 200 MP of the base model launched in 2025, using the same 5th generation Snapdragon 8 Elite chipset found in the Galaxy Fold 8 'passport'.
Regarding the Galaxy Z Flip 8, it should maintain the two cameras and the maximum battery capacity of 4,174 mAh from its predecessor. Confirmed improvements for this model include a reinforced hinge and the adoption of a Qualcomm SoC, similar to the one used in the Fold line.
Samsung is also expected to present the Galaxy Watch 9 and the Galaxy Watch Ultra. Both are expected to receive improvements in battery life and incorporate the AI insights feature from the Samsung Health app, presented in June. While the Watch 9 should maintain standard features, the new Ultra 2 promises the most powerful battery in the line, with 800 mAh, focused on outdoor activities.
Concerning the smart glasses, a prototype was previously seen, allowing interaction with Gemini, as tested by journalist Scott Stein from CNET. The design of these glasses would be under the responsibility of Gentle Monster.
The Galaxy Unpacked 2026 event will be broadcast live on the Samsung website and YouTube on Wednesday, July 22nd, starting at 10 am (Brasília time). Tecnoblog will cover the event in person, directly from London, England, by invitation from the company.
Google announced new features for the AI Mode in Search this Thursday (16th), integrating it with Canva, YouTube Music, and Instacart. These additions expand the use of artificial intelligence to facilitate users' daily tasks.
The implementation of these improvements began in the United States during July. The corporation's intention is to make AI features closer to usual activities, allowing users to trigger tools from other applications directly through the search interface, eliminating the need to open each service individually.
With these new connections, AI Mode now assists in creating playlists, developing visual content, and organizing purchases, all based on commands provided in natural language within Google Search itself.
The partnership with YouTube Music allows users to request customized playlists based on criteria such as musical style or desired mood. After processing the request, the system suggests a playlist that can be viewed in the music platform's application.
Regarding Canva, the AI tool offers support in creating visual templates, such as materials for events. Google clarified that this technology has the capacity to use the user's calendar data, when available, to adapt the templates to the specific context of the event.
Additionally, the link with Instacart allows orders placed via AI Mode to be converted into shopping lists within the application. This functionality can also take into account scheduled commitments in the calendar, such as meetings or events, to suggest items relevant to the occasion.
This expansion is part of Google's Personal Intelligence initiative, a feature that enables Gemini to use information from various applications to enrich its responses. The company began increasing this capability throughout 2026.
In addition to these integrations, AI Mode received more sophisticated search features. Among them is a smart search box designed to adapt to more elaborate queries and accept multiple input formats, including videos, images, files, and Chrome browser tabs.
The company also expressed its intention to increase the number of partners connected to the system in the future, maintaining a strategic focus on converting artificial intelligence into a cohesive tool across various spheres of digital routine.
Researchers from the University of Sheffield (England) have developed a new theory suggesting that the mysterious substance holding galaxies together may be in harmony with a hidden fifth dimension. The goal of this research is to help explain one of the greatest mysteries of modern science—the true nature of dark matter.
Dark matter has been studied by scientists for decades and inspires works of science fiction. For example, it appears as vortices capable of destroying planets in the film 'Star Trek,' or as 'dust' sustaining the multiverse in Philip Pullman's fantasy trilogy 'His Dark Materials.' Despite this, it remains one of the most unresolved problems in physics.
Although this substance has never been directly observed, scientists are confident in its existence due to its intense gravitational influence. It acts as an invisible 'cosmic glue,' ensuring the cohesion of galaxies, but its composition and properties remain unknown.
The hypothesis that this substance might exist in an additional and hidden dimension has been discussed in recent years. However, researchers from the University of Sheffield claim to have made a step forward with a new theoretical model. This study, published in the journal Physical Review D, offers an explanation for the behavior of dark matter and the difficulties in detecting it.
According to this model, dark matter exists in an extra dimension hidden near a force-carrying particle known as the dark photon. The theory posits that the specific geometry and shape of this dimension lead to the precise alignment of these particles' masses. This alignment generates a phenomenon called dark matter resonance, which researchers compare to the operation of a musical instrument vibrating strongly when reaching the correct note.
Dr. Yu-Dai Tsai, a senior researcher at Dorothy Hodgkin's Royal Society at the University of Sheffield, told Phys.org that dark matter resonance is already considered an important idea for understanding both its origin and detection methods. He noted: 'Dark matter resonance is already known as a powerful idea with the potential to change our understanding of how dark matter was produced in the early Universe and how we search for it today.'
According to the scientist, previous models treated this resonance merely as a pre-assumed hypothesis. Tsai added: 'But many previous models of resonant dark matter viewed the resonance as an assumption. This work provides a possible deeper origin for it: the resonance may stem directly from the geometry of hidden dimensions.'
Tsai also stated that this mechanism could explain why dark matter interacted much more intensely during fundamental periods of cosmic history, remaining practically undetectable today. He emphasized: 'This resonance can make dark matter interactions much stronger during critical epochs of cosmic history, such as in the early Universe. It is important that the model allows for these strong past interactions while explaining why dark matter seems so inert and difficult to detect today.'
The researchers also point out that although resonant dark matter and extra dimensions were studied separately in previous works, these models required extremely precise tuning of particle masses to function. The new study suggests that this alignment is not a coincidence nor dependent on manual adjustment, but arises naturally from the mathematical structure of the hidden dimension itself.
For Tsai, understanding this mysterious substance would mark a significant breakthrough for science. He stated: 'Understanding dark matter would be a profound breakthrough in humanity's knowledge of the cosmos and what it is made of.'
He added that the new model opens up new avenues for future research. 'Our study offers physicists new clear goals in the search for dark matter, while simultaneously linking two of the greatest ideas in fundamental physics: the mystery of dark matter and the existence of hidden dimensions.'
Beyond the implications for understanding the Universe, the researchers note that the search for dark matter stimulates the development of technologies with practical applications. These include ultra-sensitive detectors, cryogenic systems, low-noise electronics, and quantum measurement technologies, which can contribute to progress in fields such as medicine, computing, and global communications.
