Company Overview

Signal (Signal Messenger) was founded in 2013 by Moxie Marlinspike, initially as two separate projects — TextSecure (encrypted SMS) and RedPhone (encrypted calls) — which merged into Signal in 2014. In 2018, Moxie partnered with WhatsApp co-founder Brian Acton to establish the Signal Foundation, a 501(c)(3) non-profit organization. Acton provided $50 million in initial funding, ensuring Signal would remain permanently ad-free, data-free, and free from commercial pressure.

Headquartered in Mountain View, California, Signal is the world's most trusted secure communications app. It is known for default end-to-end encryption, zero metadata collection, and fully open-source code, widely adopted by privacy advocates, journalists, political activists, and enterprises worldwide.

Signal's most critical technology asset is the Signal Protocol, which has been adopted by billions of users across platforms including WhatsApp, Google Messages, and Facebook Messenger (Secret Conversations mode), making it the industry standard for end-to-end encryption.

Related products: Communication Services · Security Services

Key Milestones

  • 2013: Moxie Marlinspike releases TextSecure (encrypted SMS app) and RedPhone (encrypted calling app)
  • 2014: TextSecure and RedPhone merge into Signal with text and voice encryption
  • 2015: Signal adds video calling; Signal Desktop launched (Chrome app version)
  • 2016: WhatsApp integrates Signal Protocol, bringing default E2E encryption to billions
  • 2017: Google Messages integrates Signal Protocol for RCS end-to-end encryption
  • 2018: Brian Acton (WhatsApp co-founder) provides $50M to co-found the Signal Foundation (non-profit)
  • 2020: Massive user surge — WhatsApp privacy policy update triggers mass migration; Signal gains tens of millions of users in weeks
  • 2021: Launches Signal PINs (encrypted recovery), Blur tool (automatic face blurring), group calling
  • 2022: Launches Stories (24-hour ephemeral posts), username system (hide phone number)
  • 2023: Introduces Signal Payments (MobileCoin cryptocurrency) — beta phase
  • 2024: CDN relay service for faster media transfer; enhanced groups and channels
  • 2025: Independent sync service reduces device dependency; multi-device independent usage
  • 2026: Signal continues as the global privacy communications benchmark; steady MAU growth

Product Portfolio

💬 Signal Messenger

  • End-to-End Encrypted Communication: Fully encrypted by default — one-on-one messages, group chats, voice calls, and video calls. All content encrypted in transit and at rest
  • Disappearing Messages: Configurable auto-deletion timers and "View Once" media mode
  • Signal Stories: 24-hour ephemeral stories, also end-to-end encrypted
  • Group Features: Large groups (up to 1,000 members), group admins, invite links, approval flows
  • Username System: Connect via usernames instead of phone numbers for enhanced privacy

🖥️ Signal Desktop

  • Cross-Platform: Windows, macOS, and Linux desktop clients
  • Phone Sync: Pair with mobile via QR code for synchronized message history

🔐 Signal Protocol

  • Double Ratchet Algorithm: Core algorithm providing forward secrecy and backward secrecy — compromising keys won't decrypt past or future messages
  • X3DH Key Agreement: Extended Triple Diffie-Hellman key exchange for asynchronous secure communication
  • Industry-Wide Adoption: Integrated into WhatsApp, Google Messages, Facebook Messenger (Secret Conversations) — billions of users
  • Open Source Reference: libsignal open-source library available for audit and integration

🛡️ Signal PINs

  • Encrypted PIN Recovery: Restore Signal account identity information
  • Registration Lock: Prevent others from registering Signal with your phone number
  • Cryptographic Protection: Signal server cannot read PIN content

Core Strengths

Industry-Standard Encryption: The Signal Protocol is the most trusted end-to-end encryption protocol, adopted by platforms serving billions of users. Signal's cryptographic engineering expertise is unmatched

Truly Zero Metadata: Signal collects minimal user information — only a phone number for registration. No contact book storage, no communication frequency logging, no location tracking, no behavior analysis. This is unique among mainstream communication apps

Non-Profit Business Model: Operated by the Signal Foundation, with no ads, no data sales, no commercial pressure. Initial funding from Brian Acton ($50M); ongoing operations funded by donations. Business model is fully aligned with user privacy interests

Fully Open and Transparent: Signal's client, server, and protocol code are fully open source, allowing anyone to audit and verify security. Signal undergoes regular third-party security audits with published reports

Market Position

Signal competes with the following products in the secure communications market:

  • Telegram: Popular privacy-focused messaging app, but not E2E-encrypted by default (only Secret Chat mode); cloud-stored messages are accessible server-side
  • WhatsApp: World's largest messaging app (~2B+ MAUs), uses Signal Protocol for E2E encryption, but owned by Meta with controversial metadata collection practices
  • Mattermost: Open-source enterprise communication platform focused on security and self-hosting
  • Element (Matrix Protocol): Decentralized open-source communication platform based on the Matrix protocol with federated architecture
  • Threema: Swiss secure messaging app — no phone number required, one-time purchase fee
  • Wire: Enterprise-grade secure communication platform with E2E encryption and self-hosting support

Signal's core differentiators are: default full encryption, minimal data collection, and non-profit governance. In scenarios requiring the highest level of communication security (journalists, activists, enterprise sensitive communications), Signal is the industry's first choice.