23 October 2026 · security
Looking for a secret chat, a secure messaging app or a way to send hidden messages? However well it is protected along the way, every message ends up on a screen. Yours. Here is what happens there, and how to guard it, starting today.
On 9 March 2025, a French scientist from the National Centre for Scientific Research (CNRS) was travelling to a conference near Houston. He never made it to the venue. At the border he was stopped for a random check, and his phone and computer were searched. In the end he was denied entry and sent back to France.
According to France’s Minister of Higher Education and Research, Philippe Baptiste, the reason lay in his conversations with colleagues and friends. In them, the scientist expressed his personal opinion of the Trump administration’s research policy. The US authorities called this “blatantly false”. According to them, his device held confidential information from the Los Alamos laboratory.
Which version is true is for others to decide. But both begin the same way: the phone is in someone else’s hands. And to read another person’s encrypted chat, you don’t need to crack any code. An unlocked screen is enough.
This is not an isolated case. US Customs and Border Protection (CBP) itself publishes how many phones, laptops and other devices it has searched:
As a share of travellers, that is small: under 0.01%. As a number, it is not. And more than 47,000 of this year’s searches were “basic”. In these, the officer goes through the device by hand and does not need to have any suspicion. Since January 2026, the rules also explicitly cover smartwatches, SIM cards and USB sticks.
And here is something few people know: a traveller is required to hand over the device in a way that allows it to be inspected. If they don’t, the phone can be detained. For a foreign national, a refusal also counts in the decision on whether to let them into the country.
The border is the extreme case. The everyday one is much closer: on the café table, on the sofa at home, on the desk at work.
In 2016, researchers from Lisbon and Vancouver asked 1,381 people in the US whether they had looked through someone else’s phone without permission. They asked in a way that made it impossible to tell who had answered what, so that people would tell the truth. The finding: one in five adults had done it in just one year. Among people aged 18 to 24, it was more than half.
It takes no skill at all. Just an unlocked phone, and an owner who has stepped away for a minute. That is why people look for a secret messaging app, and not just a stronger password.
Some conversations are just for two. Flirting, a confession, a tender word at midnight, a photo that is not meant for other eyes. They are not for the children, not for colleagues, and not for whoever picks up your phone from the table. Sometimes they are not even for the person you share your home with.
Whoever goes through another person’s phone is rarely looking for bank passwords. They are looking for who you write to and what you say to each other. That is why people search for a discreet chat for intimate conversations: a place where personal things stay personal, and who writes to whom is between the two of them.
The need is clear. The question is how far the protection goes.
End-to-end encryption is a must. Without it, there is no point talking about a secure chat or private communication. It protects the message while it travels: from the server, from the network, from anyone listening in along the way.
But the journey ends on your screen. There, the message has to appear so that you can read it. And once it appears, anyone holding the phone can see it.
Most secret chat apps answer with a lock: a PIN, hidden chats, disappearing messages. The lock helps. But as soon as someone realises there is a hidden or locked chat, the question is no longer what it says, but why it is hidden.
Semanty is a chat app for encoding communication through a change of meaning in the message. It encrypts messages the way other secure chats do. The difference is what sits inside, and what stays in plain sight.
A different text on the outside. You write one thing, and out on the network sits another, perfectly normal and meaningful conversation. About the weather, the match, dinner. The real meaning comes back only for the person you write to. That way, your hidden messages don’t look hidden at all.
Panic mode in one move. You turn it on once in Settings. Then, if someone leans towards your screen, tap the name at the top of the chat three times, or shake the phone. The ordinary text is hidden, and only the everyday conversation stays. Nothing is deleted, and nothing new goes to the other person. To come back, tap three times again and confirm with your face, finger or password. How panic mode works
Two faces in front of the camera, and the chat locks. With “Panic on a stranger face”, Semanty locks itself when the camera sees two faces. It opens only with your face or finger. What “Stranger face” does
A notification with no name and no text. A message notification reads only “You have a new message”. It doesn’t say who sent it or what it says.
No number and no contacts. Semanty is a chat app without a phone number, and it doesn’t dig through your contacts. It is made for the few close people you really talk to.
Five things to do today. They work on any phone and in any app, not just Semanty. Each one takes about a minute.
Otherwise, anyone who walks past the table reads your messages without even touching the phone. In your notification settings, set previews to show only when the phone is unlocked. Menu names vary from brand to brand.
iPhone: press and hold the side button and either volume button for 2 seconds, then press the side button. Face ID stops unlocking the phone until you enter your passcode.
Android: press and hold the power button (on some phones together with a volume button) and choose “Lockdown”. Fingerprint and face unlock stop working, and notifications stay hidden until you next unlock with your PIN. On older Samsung phones, you first have to turn it on in the lock screen settings.
Thirty seconds to a minute is enough. A phone left unlocked on the table is an open letter.
For your most personal conversations. The less that stays in the chat, the less there is to read.
Back up your phone and sign out of the apps you won’t need on the trip. At the US border, only what is stored on the device itself is checked. What you don’t carry can’t be searched at the checkpoint.
Semanty is not open to everyone yet. If you are looking for a secret chat for private messaging with the people closest to you, sign up for early testing. Ideally together with the person you write to the most.
And if you found this article useful, send it to someone who leaves their phone unlocked on the table.
