How Signal Is Protecting Against Future Quantum Computers—and Today's Phishing Attacks

The Signal Foundation has added new cryptographic defenses to its messaging app, introducing something called the Sparse Post Quantum Ratchet (SPQR). The timing matters: as cybercriminals increasingly use SMS text messages to trick people into revealing security codes and unlock accounts through SIM swapping attacks—where a hacker takes control of your phone number by manipulating your carrier—Signal is moving to strengthen both current and future security.

Signal is a nonprofit organization, which means it doesn't have to balance privacy features against the need to make money. That distinction shapes how it approaches security compared to commercial messaging services like WhatsApp or iMessage, which operate within the constraints of shareholders and government regulators.

Making Device Switching Easier and Safer

Signal has made it simpler to move your account to a new phone or tablet without losing your messages. When you set up Signal on a new device, you can now transfer your chat history and media from the last 45 days—a straightforward quality-of-life feature that addresses a real friction point for users juggling multiple devices.

The platform added another privacy safeguard on Windows: a setting that prevents others from taking screenshots of your Signal window. This is particularly useful in corporate environments where people are worried about accidentally leaking sensitive information.

To access these features when you switch devices, Signal uses a PIN—a code you set up that lets you recover your entire profile, messages, contacts, and block lists. The clever part is that Signal itself never sees this data. Even during account recovery, the service cannot access what you are protecting. It's what the security industry calls a "zero-knowledge" design.

Warnings About Phishing and How to Stay Safe

Signal has started warning users more actively about phishing attacks. These often come as text messages or app notifications asking you to confirm your identity, provide a backup recovery key, or reset your password. The message usually appears to come from Signal, but it doesn't.

The platform's official advice: if you think something is suspicious, contact support only through the official Signal website. That simple friction—having to break away and verify the sender—stops most impersonation attacks cold.

This defensive posture reflects what the wider cybersecurity industry is seeing. Global spending on cybersecurity is expected to reach $240 billion in 2026, an increase of about 12.5% year over year. Phishing attacks alone cause an estimated $25 billion in losses annually, and that number is climbing as attackers get more sophisticated.

Why Quantum Computers Matter for Your Encrypted Messages

To understand what SPQR does, it helps to know what problem it solves. Today's encryption—the math that scrambles your messages so only the recipient can read them—relies on problems that are extremely hard for normal computers to crack. But quantum computers, if they ever become powerful enough, could solve those problems much faster.

We don't have practical quantum computers yet. The ones that exist today are laboratory prototypes. But cryptographers think it's worth preparing now, the same way we prepare for hurricanes by stocking supplies months in advance. Signal's SPQR is that preparation.

Signal's protocol already secures billions of messages daily, not just in the Signal app but also in other messaging services that license Signal's underlying technology. This means that when Signal improves its encryption, the benefits ripple across a much larger ecosystem of users.

Policy Pressure and Why Signal Stays Independent

Signal has openly opposed the UK's Online Safety Bill, saying the law as written would severely damage privacy and free expression. This public stance reflects a broader tension: governments want to regulate encrypted messaging for security and law enforcement reasons, but privacy advocates worry that regulation could create backdoors that harm everyone.

There's a pattern worth noting here. When Signal announced these security upgrades, it did so partly in response to regulatory pressure. Organizations tend to invest more in security research when they anticipate future restrictions on current encryption methods. It's defensive innovation.

Signal's nonprofit structure gives it flexibility that commercial platforms do not have. WhatsApp and iMessage must think about government access to markets and shareholder concerns. Signal can make decisions with user privacy as the primary goal. That difference, over time, shapes the security choices these platforms can make.

The Bigger Picture: Why This Matters Beyond Signal Users

Signal's improvements touch something larger. The Signal Protocol—the underlying cryptographic design—is used by other messaging apps. When Signal strengthens its defenses, billions of users across multiple platforms benefit. That multiplier effect makes the Signal Foundation's investments more valuable to the broader ecosystem.

The convergence of a few trends suggests what comes next. Post-quantum cryptography will become standard, not a luxury feature. SMS-based attacks will keep evolving, forcing stronger authentication methods. And regulatory frameworks around the world will continue to pressure encrypted messaging platforms. These forces will drive further innovation in how we protect messages and keep accounts secure.

The growth in cybersecurity spending reflects something straightforward: as attacks get more sophisticated, defenses have to keep pace. Signal's approach—preparing for quantum threats while educating users about today's phishing scams—addresses both the immediate risk and the one that might arrive in a decade. That's how security actually works in practice: not with a single breakthrough, but with sustained attention to evolving threats.