Signal is widely regarded as one of the most secure messaging apps available today. It uses the Signal Protocol, a state-of-the-art end-to-end encryption system, ensuring that only the sender and recipient can read the messages. Unlike some other apps, Signal minimizes data collection—only storing the phone number and a few necessary metadata—making it highly privacy-focused.

While apps like WhatsApp also employ E2EE, Signal’s open-source nature and transparency audits make it a preferred choice for privacy advocates and security experts looking for maximum security, especially for sensitive conversations. This quality also implemented by Wire, another alternative for Signal.

Signal is commonly used for secure messaging within teams and organizations, but lacks native business features like compliance logging, admin controls, and integrations demanded by enterprises. 

Businesses looking for full-featured collaboration—especially with advanced guest management and enterprise admin controls—should consider Wire, which is specifically designed for professional use cases and meets strict industry standards.

Signal enables group communication and one-to-one chats, but does not offer channels and enterprise-grade external collaboration tools such as guest user management or cross-organizational federation.

While you can create groups across organizations, business-focused platforms like Wire offer secure external guest access, granular permissions, and managed federation for cross-company workflows, making them the better fit for professional external collaboration.

Yes, Signal is fully open source; its client and server codebases are publicly available under the GNU Affero General Public License (AGPL). This transparency allows independent security researchers and auditors worldwide to scrutinize the code for vulnerabilities or backdoors, enhancing trust. Being open source also fosters a privacy-centric development approach, as issues can be identified and fixed quickly, reducing the risk of malicious code. However, it’s important to note that open-source status alone does not guarantee absolute privacy, but combined with its minimal data collection policy, it significantly boosts user confidence in Signal’s commitment to privacy.

Signal’s encryption protocol, known as the Signal Protocol, is a hybrid system combining several cryptographic techniques to ensure message security. It employs the Double Ratchet algorithm for forward secrecy and future secrecy, meaning each message session is uniquely encrypted and compromised messages cannot decrypt past conversations. It also uses pre-keys to facilitate asynchronous messaging, allowing devices to encrypt messages even when offline. The protocol encrypts not only messages but also voice and video calls, ensuring comprehensive security across all communication types. Its open algorithm design allows peer-reviewed validation, earning trust from security experts worldwide.

For enterprises needing more granular security features, compliance certifications, and customizable encryption policies, Wire extends these protocols with zero-knowledge architecture and compliance-ready solutions, making it a preferred choice for secure business communications.