London Daily

Focus on the big picture.
Thursday, Oct 02, 2025

What is Signal (WhatsApp secure-alternative), and why is it suddenly popular in Hong Kong?

What is Signal (WhatsApp secure-alternative), and why is it suddenly popular in Hong Kong?

The messaging app saw a surge in downloads after a new national security law came into force. End-to-end encryption is a key feature of the privacy-conscious app

Signal is the new app of the moment in Hong Kong.

Since June 30, the city’s residents have been flocking to the messaging app, driving it to the top spot on both Apple’s App Store and Google Play. It also saw a surge in American users who organised and participated in Black Lives Matter protests nationwide.

Here’s what you need to know about the hot privacy-conscious app.


Encryption for everyone, not just the tech-savvy

Signal was created by American cryptographer and Twitter’s former head of security Moxie Marlinspike. His goal was to build an easy-to-use digital tool that helps ordinary people keep their communications secure.

The free app is developed by a non-profit organisation supported entirely by grants and donations. Over the years, it has received close to US$3 million from the Open Technology Fund run by the US Agency for Global Media, the government agency that also oversees Voice of America.

Signal boasts millions of daily users, with US whistle-blower Edward Snowden among them. The European Commission also told its staff to switch to Signal earlier this year.

The app has already been blocked in some countries such as Egypt, Oman, Qatar and United Arab Emirates. Surprisingly, it still works in mainland China… for now.


Why are Hongkongers turning to Signal?

Late at night on June 30, Hong Kong adopted a new security law that went into effect the next day. Crafted by Beijing, the rules grant local authorities sweeping powers to crack down on acts of secession, subversion, terrorism and collusion with foreign forces. Secret surveillance can be approved by the city’s leader.

Downloads of Signal surged immediately after the legislation was unveiled. Residents told the South China Morning Post that they started taking various cybersecurity measures to protect their privacy. Some people quit social media. Others are using VPNs – software that allows users to hide the origin of their traffic by encrypting and re-routing it.


Is Signal really secure?

Signal uses end-to-end encryption, just like WhatsApp and iMessage. That means when you send a message, it’s scrambled into a series of unreadable codes that make no sense to anyone who intercepts it during transmission. Only the intended recipient has the key to decrypt and read the message. Hackers, police, your phone company and even Signal itself are all unable to see the content of whatever you send.

The code behind Signal is open source, meaning researchers are free to examine for flaws. It’s widely held up as an example of sound encryption. WhatsApp’s encryption is even based on the Signal Protocol.

Signal also famously encrypts metadata that other messengers like WhatsApp don’t. So the organisation can’t even see who is talking to whom or when.

In 2016, US prosecutors issued a federal subpoena to the group behind Signal, requesting data on two suspects using the app. Authorities sought information that included names, phone numbers, email addresses and IP logs. None of the data was turned over, according to court filings published by the American Civil Liberties Union.


Can’t I just use other end-to-end encrypted messaging apps?

You can, but there are some features that make Signal unique.

For one, Signal conversations are only stored locally on devices. This contrasts with WhatsApp, for example, which lets users back up their chat records on iCloud or Google Drive, neither of which adopt end-to-end encryption for all data. Apple, however, has stressed that only the company itself holds the encryption key to iCloud data.

Signal also offers a few options for additional layers of protection. A photo or video can be set to automatically delete after it’s been viewed. You can also turn on disappearing messages, which will erase messages after a set period of time – anywhere from five seconds to a week.

Signal also recently introduced a blur feature in the image editor. This hides the faces of people shown in a photo with a fuzzy box.


I use Signal, so I can relax, right?

All technology has limits – even Signal.

As much as you value privacy, the people you message can always take screenshots of your conversations or save images you sent without telling you. Also, if their phones are compromised, any data on their device – including your chat history and phone number – could also be exposed.

Newsletter

Related Articles

0:00
0:00
Close
Trump Administration Launches “TrumpRx” Plan to Enable Direct Drug Sales at Deep Discounts
Trump Announces Intention to Impose 100 Percent Tariff on Foreign-Made Films
Altman Says GPT-5 Already Outpaces Him, Warns AI Could Automate 40% of Work
Singapore and Hong Kong Vie to Dominate Asia’s Rising Gold Trade
Trump Organization Teams with Saudi Developer on $1 Billion Trump Plaza in Jeddah
Manhattan Sees Surge in Office-to-Housing Conversions, Highest Since 2008
Switzerland and U.S. Issue Joint Assurance Against Currency Manipulation
Electronic Arts to Be Taken Private in Historic $55 Billion Buyout
Thomas Jacob Sanford Named as Suspect in Deadly Michigan Church Shooting and Arson
Russian Research Vessel 'Yantar' Tracked Mapping Europe’s Subsea Cables, Raising Security Alarms
New York Man Arrested After On-Air Confession to 2017 Parents’ Murders
U.S. Defense Chief Orders Sudden Summit of Hundreds of Generals and Admirals
Global Cruise Industry Posts Dramatic Comeback with 34.6 Million Passengers in 2024
Trump Claims FBI Planted 274 Agents at Capitol Riot, Citing Unverified Reports
India: Internet Suspended in Bareilly Amid Communal Clashes Between Muslims and Hindus
Supreme Court Extends Freeze on Nearly $5 Billion in U.S. Foreign Aid at Trump’s Request
Archaeologists Recover Statues and Temples from 2,000-Year-Old Sunken City off Alexandria
China Deploys 2,000 Workers to Spain to Build Major EV Battery Factory, Raising European Dependence
Speed Takes Over: How Drive-Through Coffee Chains Are Rewriting U.S. Coffee Culture
U.S. Demands Brussels Scrutinize Digital Rules to Prevent Bias Against American Tech
Ringo Starr Champions Enduring Beatles Legacy While Debuting Las Vegas Art Show
Private Equity’s Fundraising Surge Triggers Concern of European Market Shake-Out
Colombian President Petro Vows to Mobilize Volunteers for Gaza and Joins List of Fighters
FBI Removes Agents Who Kneeled at 2020 Protest, Citing Breach of Professional Conduct
Trump Alleges ‘Triple Sabotage’ at United Nations After Escalator and Teleprompter Failures
Shock in France: 5 Years in Prison for Former President Nicolas Sarkozy
Tokyo’s Jimbōchō Named World’s Coolest Neighbourhood for 2025
European Officials Fear Trump May Shift Blame for Ukraine War onto EU
BNP Paribas Abandons Ban on 'Controversial Weapons' Financing Amid Europe’s Defence Push
Typhoon Ragasa Leaves Trail of Destruction Across East Asia Before Making Landfall in China
The Personality Rights Challenge in India’s AI Era
Big Banks Rebuild in Hong Kong as Deal Volume Surges
Italy Considers Freezing Retirement Age at 67 to Avert Scheduled Hike
Italian City to Impose Tax on Visiting Dogs Starting in 2026
Arnault Denounces Proposed Wealth Tax as Threat to French Economy
Study Finds No Safe Level of Alcohol for Dementia Risk
Denmark Investigates Drone Incursion, Does Not Rule Out Russian Involvement
Lilly CEO Warns UK Is ‘Worst Country in Europe’ for Drug Prices, Pulls Back Investment
Nigel Farage Emerges as Central Force in British Politics with Reform UK Surge
Disney Reinstates ‘Jimmy Kimmel Live!’ after Six-Day Suspension over Charlie Kirk Comments
U.S. Prosecutors Move to Break Up Google’s Advertising Monopoly
Nvidia Pledges Up to $100 Billion Investment in OpenAI to Power Massive AI Data Center Build-Out
U.S. Signals ‘Large and Forceful’ Support for Argentina Amid Market Turmoil
Nvidia and Abu Dhabi’s TII Launch First AI-&-Robotics Lab in the Middle East
Vietnam Faces Up to $25 Billion Export Loss as U.S. Tariffs Bite
Europe Signals Stronger Support for Taiwan at Major Taipei Defence Show
Indonesia Court Upholds Military Law Amid Concerns Over Expanded Civilian Role
Larry Ellison, Michael Dell and Rupert Murdoch Join Trump-Backed Bid to Take Over TikTok
Trump and Musk Reunite Publicly for First Time Since Fallout at Kirk Memorial
Vietnam Closes 86 Million Untouched Bank Accounts Over Biometric ID Rules
×