Paper notes, notes apps and an unlocked phone

Nobody memorises a long passphrase or a long address. It gets written down somewhere, and where it gets written down decides who can read it.

This card takes no side on paper. Paper is neither the naive option nor the wise one, and both of those positions get argued confidently by people who have thought about only half of it. Paper has genuine advantages and genuine weaknesses, and they are different in kind from the advantages and weaknesses of a file.

What paper is good at: it does not sync, it does not get backed up to an account you forgot about, it does not appear in a search, and it is not readable from anywhere except the place it physically is. What paper is bad at: it is readable by anyone in that place, it has no lock, it does not know who read it, and it persists in drawers and jacket pockets long after anybody has thought about it.

Where the small written things end up

A scrap of paper

In a drawer, a wallet, a book, or under something. Read by whoever is in the room. No record of having been read.

A notes app

Almost always synced to an account by default, which puts a copy on every signed-in device and on a server. See backups and sync.

A message to yourself

A durable record in a messaging account, often on two devices, often included in a backup, and visible in a notification preview.

A photo of a screen

A file in the camera roll, dated, usually with location metadata, and swept into the same sync as every other photo.

A browser bookmark

A synced item on any machine signed into the same browser profile, and visible in the bookmark bar to anyone who opens it.

The pattern in that table is that the digital options are more private against a person in the room and much less private against everything else, while paper is the reverse. That is the whole trade and there is no option that wins both sides of it.

The unlocked phone

A phone lying face up on a table with no lock screen is not really a device at that moment, it is an open notebook. Anybody who picks it up has the messages, the photos, the notes and the browser, without needing to do anything clever. This is the highest-exposure item in the entire section and it is also the one with the simplest fix.

A locked phone is a different object. It shows notification banners, a separate exposure covered in lending the machine, and it shows nothing else. The gap between locked and unlocked is close to the only place in this catalogue where one setting changes an outcome that completely.

The everyday version of this is not a stranger. It is a partner picking up the wrong phone, a child playing a game, a colleague answering a call for you, or somebody handing it back and glancing at what is showing. None of that involves anybody deciding to look at your things.

What a person who finds a note actually learns

Less than the panic suggests, and it depends entirely on what the note says. A string of characters with no label is close to meaningless to somebody who is not looking for it. A string of characters under a heading naming a site is a complete disclosure. The label does more work than the content in almost every case.

What they do not learn from a note is anything about activity. A written address says a thing exists, not that anybody used it. An order number is a reference to a record they cannot see. A passphrase on paper is only useful to somebody who also has the thing it opens and knows that it opens it.

They also do not necessarily learn that the note is current. Paper accumulates, and most of what is in a drawer is out of date. That cuts both ways, because it also means a note you thought you dealt with may still be sitting there.

What changes the answer

6 things change how much this action gives away. None of them takes it to zero, and none of them is a promise.

1. Decide the lifetime when you write itThe useful question at the moment of writing is how long this needs to exist: one hour, one week, or permanently. Most notes are written as if permanent and needed for an afternoon. Deciding at the start is what makes disposal actually happen, because a note with no intended end date never has an obvious moment to go.
2. Do not label the thingA value without a heading is far less legible than the same value with one, and the heading is almost never necessary for you. This is about not building a durable artifact that explains itself. It does nothing if the value is self-evidently what it is.
3. Know whether your notes app syncsMost do, by default, without ever saying so on screen. That turns one note into copies on every signed-in device and a copy on a server. Backups and sync covers what that actually means. Checking is a one-off, and it does not change copies that already exist.
4. Lock the phoneThis is the largest single change in the card and it is a setting rather than a habit, so it holds on the days you are not thinking about it. It does nothing about notification content on the lock screen, which is configured separately.
5. Prefer transient to durable, where it worksReading something off a screen and typing it once leaves nothing behind. Copying it leaves a clipboard entry, which the clipboard card covers. Writing it down leaves an object. Each step up is a real increase in what exists, and sometimes the durable version is genuinely the right choice.
6. Deal with the drawerOld notes are the most common finding in this card, because nobody plans to keep them and nobody plans to get rid of them either. Going through the places small pieces of paper accumulate is unglamorous and it removes real objects. It says nothing about what is on any device.

What this card is not

This card does not tell you to use paper or to avoid it. It sets out what each option is exposed to, because the two options are exposed to different things.

Questions that come up

Is paper better than a password manager?

They fail differently. Paper is exposed to whoever is in the room and to nothing else. A manager is exposed to the device it is on, to whatever it syncs with, and to the strength of one passphrase. This card does not rank them and does not recommend products.

What about a photo of a handwritten note?

That combines both weaknesses. The paper still exists in the room, and the photo goes into the camera roll with a date and usually a location, then into whatever the photos sync with. It is the least useful of the available options.