Signal

Signal

Privacy-focused messaging platform with end-to-end encryption

Overview

Signal is a privacy-focused messaging platform that provides secure, encrypted communication for individuals and groups. It uses state-of-the-art end-to-end encryption so messages and calls can only be read or heard by the intended recipients. The platform supports voice and video calls, group chats, and encrypted stickers, all without long-distance charges. Signal operates as an independent nonprofit and does not rely on ads, data selling, or user tracking; it is funded through grants and donations. This makes privacy an integral part of its operations rather than a feature. Signal aims to give people a reliable, private way to communicate without surveillance or data collection.

About Signal

Simplify's Rating
Why Signal is rated
B-
Rated B on Competitive Edge
Rated B on Growth Potential
Rated C on Differentiation

Industries

Consumer Software

Social Impact

Cybersecurity

Company Size

51-200

Company Stage

N/A

Total Funding

$50M

Headquarters

Indianapolis, Indiana

Founded

2013

People at Signal

People at Signal who can refer or advise you

Simplify Jobs

Simplify's Take

What believers are saying

  • Signal deployed in-app warnings for messages from unknown contacts to combat rising social engineering attacks (June 2026).
  • Signal introduced the Triple Ratchet protocol with post-quantum cryptography to protect against future quantum computer hacks (March 2026).
  • Security experts recommend enabling Registration Lock as a critical defense against recent backup key phishing campaigns (May 2026).

What critics are saying

  • Russian intelligence-linked phishing steals backup keys to decrypt historical messages, targeting journalists and officials; high impact within 6–12 months.
  • Backup key phishing is expanding to ordinary users, increasing exposure risk for average Signal users within 3–6 months with medium impact.
  • Successful social engineering attacks may erode trust in Signal's encryption model, driving high-risk users to competitors like WhatsApp within 12–18 months.

What makes Signal unique

  • Signal is a nonprofit independent messaging platform with no ads, user tracking, or revenue from data selling.
  • End-to-end encryption is mandatory and integrated into Signal's core operations, not an optional privacy feature.
  • Signal does not allow acquisition by major tech companies and relies solely on grants and donations for funding.

Help us improve and share your feedback! Did you find this helpful?

Funding

Total Funding

$50M

Above

Industry Average

Funded Over

1 Rounds

Angel funding comparison data is currently unavailable. We're working to provide this information soon!
Angel Funding Comparison
Coming Soon

Benefits

Remote work flexibility

Healthcare, vision, and dental

401(k)

Growth & Insights and Company News

Headcount

6 month growth

0%

1 year growth

2%

2 year growth

0%
Bulletproof Servers
Jun 27th, 2026
FBI: Russian hackers now target Signal backup recovery keys

FBI: Russian hackers now target Signal backup recovery keys. Jun 27, 2026 // 01:16 - Niko Dunn The FBI and CISA are warning that a phishing campaign targeting Signal users tied to Russian intelligence services has evolved to steal Signal Backup Recovery Keys, allowing attackers to access victims' historical messages. The updated public service announcement is an update to a March 2026 advisory that warned the threat actors were targeting users of commercial messaging applications, particularly Signal, through phishing campaigns designed to hijack accounts rather than break end-to-end encryption. "RIS cyber threat actors continue to masquerade as automated CMA support accounts in updated phishing messages but have evolved their tactics to attempt to elicit victims' Backup Recovery Keys," warns an FBI PSA published today. According to the FBI, the campaign continues to target individuals of high intelligence value, including current and former US and international government officials, military personnel, political figures, journalists, and key officials located in Ukraine. The agencies attribute the activity to Russian Intelligence Services (RIS), including officers embedded with Russia's Federal Security Service (FSB) Border Guards and other actors working on behalf of the Russian military. The campaign is publicly tracked as UNC5792 and UNC4221. While the original advisory focused on phishing messages that attempted to steal verification codes or account PINs, or to trick users into linking attacker-controlled devices to their Signal accounts, the updated alert says the attackers have evolved their tactics. The FBI says the threat actors continue to impersonate Signal support teams, sending phishing messages that falsely claim Signal is introducing mandatory two-factor verification following an alleged wave of attacks by hackers from Iran and post-Soviet countries. "Recently, attempts to hack users of our messenger with the connection of third-party devices to the account have become more frequent," reads the initial phishing message. "An investigation conducted jointly with the US government and European partners revealed that the attacks on accounts were carried out by hackers from Iran and post-Soviet countries. In this regard, Signal updates Terms of Service & Privacy Policy, and introduces Mandatory Two-factor Verification for users." "Not to lose your messages and media, set up your Signal Backup (Settings -> Backups -> Enable backups -> View recovery key -> Copy to clipboard -> Next -> Enter the recovery key -> Next -> Continue -> Choose your backup plan). Click the "Accept" button in the pop-up and stay tuned for security updates on our messenger." When a target follows these instructions, their Signal messages are backed up using Signal's Secure Backups feature, which stores encrypted copies of conversations on Signal's cloud servers. The data is end-to-end encrypted using the recovery key created in the steps above and should never be given to anyone else, as anyone with the key can use it to recover the backed-up data on their own devices. The threat actors later send a second phishing message, still posing as Signal support, warning that your data is at risk of loss due to a synchronization issue. "Your Signal Account data (messages and media) is at risk of permanent loss due to a sync issue," reads the second Signal message. The threat actors then prompt you to go into the Backup settings, copy your recovery key to the clipboard, and paste it into the message to prevent the loss of your stored data. However, once you provide your recovery key, they can restore the backup to their own devices and gain access to the victim's historical messages, including private and group conversations. The updated advisory also warns of a recovery scenario that users may miss after their account was compromised. The FBI warns that if an attacker obtains a user's Backup Recovery Key, creating a new Signal account using the same phone number does not invalidate the old stolen key. Instead, users must generate a new Backup Recovery Key through Signal's backup settings, which invalidates the previous key for future backup downloads. However, the agencies warn that generating a new recovery key will not prevent attackers from accessing backups they already downloaded using the compromised key. The updated advisory reminds users that legitimate messaging application support teams only communicate through official company email addresses, never request verification codes within the application, and do not send links asking users to verify or restore their accounts. Anyone who believes they have fallen victim to the campaign is encouraged to report the incident to the FBI's Internet Crime Complaint Center (IC3), a local FBI field office, or CISA.

Moore County News Press
Apr 25th, 2026
What is Signal and is it secure?

What is Signal and is it secure? * AFP AFP * 1 hr ago * 0 Signal, an end-to-end encrypted messaging app long considered one of the most secure in the world, has recently faced attacks from hackers accused of links to Russia. Top German officials on Saturday blamed Moscow-backed groups for phishing attacks targeting senior politicians on the messaging app, raising questions about how secure Signal really is. Discover more Local News Pet supplies local Custom local apparel

The Tech Outlook
Mar 9th, 2026
Signal Confirms Phishing Attacks Targeting Accounts of Government Officials and Journalists

Signal confirms phishing attacks targeting accounts of government officials and journalists. By Divya Dhingra Published on March 9, 2026, 23:31 IST Last updated March 9, 2026, 23:32 IST Signal, which is a free messaging app focused on maximum user privacy, has confirmed that several users, including some government officials and jurnalists have been targeted in a phishing attack, which has resulted in account takeovers of some users. Here is more to it. Signal confirms phishing attacks. In a statement published via its official X handle, Signal clarified that its encryption and infrastructure have not been compromised. The attacks were carried out through sophisticated phishing campaigns, in which users were tricked into sharing account information such as SMS codes and/or Signal PINs, allowing attackers to gain access to their accounts. Signal explained that attackers may impersonate a Signal support bot - which does not exist - and request users to share their SMS verification code or PIN. Sharing such information gives attackers access to your account. For those unfamiliar, Signal only requires an SMS verification code during the initial account setup. Therefore, if you receive a message asking for your SMS verification code at any other time, it is likely a scam/phishing attack. The company emphasises never sharing your SMS code or PIN with anyone. Signal will never request these details except during account sign-up. In short, if you receive a message requesting your PIN, password, or SMS code, ignore it. Signal also mentioned that it is actively working on adding clear visual and text-based warning signs within the app to alert users to potential risks, especially phishing. This feature aims to help users identify suspicious messages and avoid sharing sensitive information. Stay tuned for more updates!

PayForEssay
Mar 6th, 2026
Enhance your secure communication with safew电脑端: the ultimate solution for privacy-conscious users.

Enhance your secure communication with safew电脑端: the ultimate solution for privacy-conscious users. 2026年3月6日 by Admin In an era where digital privacy is more critical than ever, finding a reliable and secure instant messaging platform is paramount. safew电脑端 stands out as a pioneering application designed to meet the needs of users who prioritize confidentiality and security in their communications. Developed with cutting-edge encryption protocols, safew offers a seamless, encrypted messaging experience that rivals the most prominent platforms like Signal and Telegram, but with an added focus on user sovereignty and data protection. Why choose safew电脑端 for secure messaging? The safew电脑端 application delivers industry-leading security features, including end-to-end encryption, multi-factor authentication, and persistent security updates. Its user-friendly interface ensures that even those new to secure communication tools can easily navigate and leverage its full potential. Moreover, safew's commitment to open-source principles guarantees transparency, allowing security experts to verify its codebase regularly. Key features and benefits. * Robust Encryption: Safew employs advanced cryptographic techniques to safeguard your messages from interception or unauthorized access. * Cross-Platform Compatibility: Access safew via desktop and mobile devices for versatile, on-the-go communication. * Privacy-Focused Design: With ephemeral messaging and minimal data retention policies, safew ensures your conversations remain private. * Secure File Sharing: Share documents, images, and multimedia securely without fear of data leaks. Comparison with other secure messaging solutions. While many secure messaging apps exist, safew.jpg offers a comprehensive blending of security, usability, and interoperability. Unlike some platforms that sacrifice ease of use for security, safew's intuitive interface ensures quick adoption for both novices and tech-savvy users. Security audits and real-world testing by leading cybersecurity firms underscore safew's reliability in protecting sensitive information. How to get started with safew电脑端. Getting started is straightforward. Visit the official website to download the safew电脑端 application. Follow the setup instructions, create your account, and immediately start secure messaging. For enhanced privacy, consider integrating safew with your existing security tools and ensure your device's security patches are up-to-date, as recommended by cybersecurity experts such as Kaspersky. Why rely on trusted resources like Pay For Essay. Ensuring the quality and reliability of your digital tools is essential, especially when handling sensitive communications. Websites like Pay For Essay provide valuable academic and technical writing services, reinforcing the importance of accuracy and professionalism in content creation. Whether you're writing technical reviews or enhancing your cybersecurity knowledge, leveraging reputable sources ensures your information remains trustworthy and authoritative. FAQs about safew电脑端 and secure messaging. * Is safew电脑端 free to use? - Yes, safew offers a free version with essential security features. Premium options may include additional functionalities and priority support. * How does safew ensure user privacy? - Safew employs end-to-end encryption, minimal data collection, and open-source transparency to maintain user privacy and security. * Can safew be used for business communication? - Absolutely. Its secure environment makes safew suitable for confidential business messaging and file sharing, ensuring compliance with enterprise security standards.

Dutch IT Channel B.V.
Oct 17th, 2025
Signal launches Triple Ratchet: quantum protection against future hacks.

Signal launches Triple Ratchet: quantum protection against future hacks. The Signal Protocol, the backbone of end-to-end encryption for billions of private messages worldwide, has received a groundbreaking upgrade. With the introduction of the Sparse Post Quantum Ratchet (SPQR), the Signal developers are building upon a Triple Ratchet protocol. This addition makes communication via the protocol resistant to future threats from powerful quantum computers, while preserving the fundamental security principles of Forward Secrecy (FS) and Post-Compromise Security (PCS). FS protects past messages from future breaches, while PCS protects future messages from a compromise in the present or past. This 'resilience' is crucial for the security of long-term chat sessions. Closing the future security gap. Earlier this year, Signal already introduced PQXDH, a first step towards quantum resistance that ensured new chat sessions use quantum-safe cryptographic keys. This protects against so-called 'harvest-now-decrypt-later' attacks, where encrypted data is stored now in the hope of decrypting it later with a quantum computer. However, the new SPQR ratchet addresses security during an ongoing session. The original Signal Protocol used Elliptic Curve Diffie-Hellman (ECDH) for continuously generating new, irreversible keys (the 'ratcheting'). Although ECDH is currently secure, it is not quantum-resistant. If a malicious actor (such as 'Mallory') in the future were to possess a powerful quantum computer, she could derive the ECDH secrets from recorded communication, meaning a session would never 'recover' from a compromise after a breach. The SPQR ratchet replaces the ECDH method with a quantum-safe method based on a Key-Encapsulation Mechanism (KEM), specifically ML-KEM 768. The birth of the 'Triple Ratchet' Instead of replacing the existing, proven Double Ratchet, Signal chose to run SPQR alongside it. This results in the Triple Ratchet protocol, where the keys from both ratchets are mixed through a Key Derivation Function (KDF). 'An attacker must now break both our elliptic curve and ML-KEM to even distinguish this key from random bits. This gives us hybrid security,' according to Graeme Connell and Rolfe Schmidt from Signal. For the average Signal user, the rollout of this new protocol means no change in the app experience. Through a smart, gradual rollout, all conversations will automatically and in the background migrate to the new, quantum-resistant protocol. Efficiency and formal verification. The implementation of the quantum-safe ML-KEM in a ratcheting protocol presented the developers with significant technical challenges. The quantum-safe keys are significantly larger at over 1000 bytes than the 32 bytes of ECDH, which has a major impact on bandwidth. To address this, Signal developed the ML-KEM Braid protocol. This uses erasure codes to split large key blocks into small, redundant 'chunks'. This allows the data to be sent efficiently and in parallel, even if messages are lost, without undermining security. Additionally, the mechanisms were designed so that generating new secrets does not happen too quickly, to prevent too many future 'epoch' secrets from becoming vulnerable simultaneously in a one-time breach. Given the complexity of the new mechanisms, Signal integrated formal verification of the protocol with partners such as PQShield, AIST, NYU, and Cryspen. This process, where protocol models are verified with software like ProVerif and F*, ensures that the new architecture provides the required quantum-safe and classical security guarantees before the code is rolled out. With this step, Signal reinforces its position as a leader in the field of cryptographic security, proactively prepared for the quantum era.

Recently Posted Jobs

Sign up to get curated job recommendations

There are no jobs for Signal right now.

Find jobs on Simplify and start your career today

We update Signal's jobs every few hours, so check again soon! Browse all jobs →