On Easter Monday in 1958, a man named Leslie Linder was staring at a page of symbols he had been failing to read for years. Then he noticed two things he could read: the Roman numerals XVI and the year 1793. That was the year Louis XVI was executed. It gave him eight letters of the alphabet, and by midnight he had cracked a code that had kept a journal private for more than seventy years. The journal belonged to Beatrix Potter, who had started it as a teenager.
If you’ve ever felt a little silly for wanting a lock on your journal, it might help to know you’re in very good company. Some of the most famous diarists in history went further than a lock. They invented their own alphabets.
Anne Lister: a code for the parts that could cost her everything
Anne Lister, a landowner in Halifax, England, kept a diary from 1806 until her death in 1840. It runs to more than 5 million words across 26 volumes. About a sixth of it is written in what she called her “crypthand,” a code she first devised as a schoolgirl in York. It mixed Greek and Latin letters, mathematical symbols, punctuation and signs of the zodiac, with no spaces between words.
The code was where she wrote her deepest emotions and her relationships with women. In early nineteenth-century England, those pages were not something she could risk anyone reading.
Decades after her death, a descendant named John Lister, working with a schoolteacher named Arthur Burrell, found a scrap of paper where Anne had written “In God is my” followed by one word in code. They guessed the word was “hope,” which gave them four letters, and the rest of the cipher followed. What they read alarmed John so much that he hid the diaries behind a panel at Shibden Hall, where they stayed until his death in 1933. Today the diaries are on UNESCO’s Memory of the World Register, and they inspired the TV series Gentleman Jack.
Beatrix Potter: one thing that was entirely hers
Potter kept her coded journal from about age 14 until she was 30, from 1881 to 1897, long before Peter Rabbit. Her mother wanted a quiet, obedient daughter, and the journal gave Beatrix something she rarely had: complete control over one small part of her life.
What’s striking is how ordinary much of it is. Alongside her observations of art exhibitions, people and the natural world, the coded papers include things like an American gingerbread recipe and poems by Robert Burns and James Hogg, copied out for practice. She wasn’t hiding a scandal. She was keeping a room of her own on paper.
Linder started working on the code in 1952, broke it in 1958, and then spent years carefully translating it, checking plants with botanists and tracing her journeys on maps, before publishing The Journal of Beatrix Potter in 1966. The best detail of all comes from Potter herself. In 1943 she wrote to her cousin that she could no longer read her own cipher, “even with a magnifying glass.”
Samuel Pepys: shorthand, plus a second layer
Samuel Pepys kept his famous diary through the 1660s, covering the plague of 1665 and the Great Fire of London. He wrote it in a shorthand system called tachygraphy, devised by Thomas Shelton. Shorthand was partly about speed, but it also meant the diary couldn’t be easily read by anyone who picked it up.
For the most intimate passages, Pepys added a second layer, switching between languages mid-sentence on top of the shorthand. A lock on the outside, something harder underneath.
The irony came later. In the 1820s a student named John Smith spent three years, from 1819 to 1822, deciphering the diary for its first publication. The whole time, the textbook Pepys had learned the shorthand from was sitting on a shelf above his head.
Isaac Newton: 57 sins, in shorthand
Around 1662, when he was about 19, Isaac Newton wrote a list of his sins in a small notebook, using the same Shelton shorthand. The notebook is now held at the Fitzwilliam Museum in Cambridge, and the list was deciphered by the historian Richard Westfall.
There are 57 entries, and most of them are wonderfully small. “Making pies on Sunday night.” “Punching my sister.” “Robbing my mothers box of plums and sugar.” One of the greatest scientific minds in history wrote in shorthand for the same reason a lot of us journal: to be honest about the petty, human stuff we wouldn’t say out loud.
The Tolstoys: when everyone reads everyone’s diary
On the eve of their wedding, Leo Tolstoy gave his fiancée Sophia his diaries, including detailed accounts of his past relationships. It was meant as honesty. It set up a marriage in which diaries were never quite private.
By 1910, writer James Meek notes in the London Review of Books, Tolstoy was “one of eight people keeping supposedly private diaries” at the family estate. The crisis of that final year was, in Meek’s words, a struggle for control of his diaries, and at one point they were deposited in a bank vault in Tula. According to his translator R. F. Christian, it was only in those last months, at 82, that Tolstoy tried for the first time to keep a diary for himself alone.
It’s a sad, very human detail. Once you know someone reads your journal, you start writing for them. It took Tolstoy most of his life to get a page that was only his.
And one that wasn’t a code at all
Leonardo da Vinci’s mirror writing often gets described as a secret code. Most experts don’t think so. Leonardo was left-handed, and writing right to left kept him from smudging the ink. Anyone with a mirror could read it. It’s a useful reminder that something can look secret without being secure.
What the old diarists knew
Put these stories side by side and a few patterns show up.
Privacy is what made the honesty possible. Lister’s code held her truest pages. Newton’s held his pettiest. Either way, the writing only happened because they believed nobody else would read it.
The reader they worried about was usually close. A mother. A spouse. A family. Not strangers or spies. That’s still true for most people today: the person most likely to read your journal is someone who can pick up your phone.
Every homemade code broke eventually. All it took was time and someone motivated, plus one lucky guess like “hope” or “XVI.”
Their journals outlived them. Lister and Potter were both read, in the end, by people they never chose. Neither got a say in it.
A modern version of their habits
Decide who your journal is for
For most people the answer is “only me.” Saying it clearly, even just to yourself, makes it easier to notice when you’ve started writing for an imagined reader instead.
Think about your realistic reader
Like Potter’s mother or Sophia Tolstoy, it’s probably someone close who could pick up your phone or notebook. Protect against them first, not against an imaginary hacker.
Use two layers, like Pepys
A passcode on your phone is the outer door. A separate lock on the journal itself is the second layer, so an unlocked phone doesn’t mean an open journal.
Keep it out of shared places
Shared cloud folders, a family account, or a tablet logged in to the same account as your phone can all quietly widen who has access.
Don’t rely on looking hidden
A vague file name or a hidden folder slows someone down, the way mirror writing might. It doesn’t stop a curious reader. Real encryption is a different thing from a clever disguise.
Decide what happens to it later
Lister and Potter never chose who would read them. It’s worth deciding for yourself whether old journals get kept, passed on or destroyed, and telling someone you trust.
If you’re hiding your journal from someone who checks your phone, controls who you talk to, or makes you afraid of how they’ll react, a better code or a locked app isn’t a safety plan. In the US, the National Domestic Violence Hotline is free and confidential: call 1-800-799-7233, text START to 88788, or chat at thehotline.org. They can also help you think through phone and online safety. If you’re in immediate danger, call 911.
Where Yasura fits
I build Yasura, a journal app, so read this part with that in mind. Lister and Potter had to invent their own alphabets. Today the code part can be handled by encryption, which isn’t a clever alphabet that one lucky guess can unravel. Yasura works 100% offline, with no account and no cloud. Your journal is encrypted on your device, and you can lock it with a PIN, Face ID or fingerprint. Decoy Mode is the second layer, for the moment someone else picks up your phone.
But Potter kept her journal private for years with a homemade code and a desk. A notebook works too. What matters is having one place where you don’t have to perform for anyone, which is exactly what these diarists went to so much trouble to protect.
Sources: Explore Your Archive, “Anne Lister: the secret’s out!”; Visit Calderdale, “The Secret Diaries of Anne Lister”; National Trust, “Cracking Beatrix’s coded writing”; Atlas Obscura, on Leslie Linder and Potter’s journal; Dickens Code project, “The Shorthand of Samuel Pepys”; Wikipedia, John Smith (priest, born 1799); The Newton Project, Fitzwilliam Notebook; Smithsonian Magazine, “Isaac Newton’s Laundry List of Sin”; Wikipedia, Sophia Tolstaya; James Meek, “Some Wild Creature,” London Review of Books; R. F. Christian (ed.), Tolstoy’s Diaries, Volume II; Artnet, “Why Did Leonardo Use Mirror Writing?”; National Domestic Violence Hotline.
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