When you sit down to write a letter on Dear Tomorrow, you're sharing something real, hopes, fears, things you might not say out loud. So we made sure that the moment you hit send, your words are sealed in a way that only one person can ever open: the person you wrote it for. Before your letter even leaves your device, your browser quietly scrambles it into an unreadable tangle of characters using a technique called encryption. Think of it like your words being folded into a secret language that only a very specific key can unlock. That scrambled version is the only thing that ever reaches our servers, and without the key, it's completely meaningless to anyone, including us.

That key? It never lives on our servers at all. Instead, it travels tucked inside the link we send your recipient, sitting after the # symbol in the URL, a part of an address that browsers are specifically designed to keep to themselves and never share with servers. So when your recipient clicks their link, the key is already there waiting in their browser. Their device uses it to quietly unscramble your letter, just for them, right there on their screen. The whole process happens invisibly and in an instant, but the effect is profound: your letter goes from you, to them, with nobody in between able to read a single word.

We built it this way on purpose. We believe your most honest words deserve a space that feels genuinely safe, not just probably private, but provably private. You shouldn't have to trust that we won't read your letters; the system is built so we mathematically can't. Once a letter is delivered, we even delete the key from our records entirely. Your thoughts, your feelings, your future, they belong to you.