A minimal PDF
Two identical pages carrying the bones of an invoice in plain shapes, and not a word of text: a file of a dozen kilobytes, with no font embedded.
A document that asks for a password before it opens
Picture a building with two doors. The street door is the one without which nobody gets in at all, and nobody sees what is inside. The door of the office at the far end of the corridor is the other one: everybody walks past it, and only the person who can unlock it goes in. A PDF has both, and the document below is the street door. Open it and you are asked for a password; until something correct is typed there, the reading software shows an empty window.
Nothing sees inside it, and that is the whole point: no preview in the file manager, no first page in the search results of your machine, no small picture of it anywhere — which is why this page has no picture of it either. Send it as an attachment and the same holds all the way along: whoever is handed it by mistake holds a file and nothing else. That is the form used for a payslip sent by e-mail, for a bank statement, for a medical report. The file travels, and the password travels another way. And there is no back door: nobody here, and nobody who wrote your reading software, can open it for you. The one other way in is the author's password, which a document may also carry; this one carries it, and prints it on its own page beside the first, because it is an example written to be looked at.
What this example shows
- The password it asks for, typed into your reading software exactly as it is written here, letter for letter and with the space in the middle: “the reader”.
- Nothing shows a page of it without that password: not your file manager, not the search of your machine, not this page.
- Every word of it scrambled inside the file, the scrambling worked out from the password, which is written nowhere in the file.
The source code, complete
Nothing is left out and nothing is simplified: this is the program exactly as it runs, for the developer who uses this library. The third is the description itself: a plain list of what the page has to say, which is what the service is sent.
Read the Rust source Read the Python source Read the JSON source
The document itself
Open the document in English Open the document in French
The other document of this pair
The other one opens for everybody with nothing typed, and asks the reading software not to let its text be copied or altered. That is a request and not a lock: software that pays no heed to it copies the page all the same. It is the one most documents calling themselves protected actually carry.
There is no picture of this document to show here: nothing draws a page of it until its password is typed in, and that is what it is for. Open it and your reading software will ask you for one. Type it exactly as it is written here, letter for letter and with the space in the middle: “the reader”.
This document weighs 13.3 kB
A password adds no chapter to a document: it weighs what the same page weighs unlocked. See the size of every example document.
Examples near this one
Showing page one before the file has arrived
The same document written twice, the ordinary way and with its first page moved to the head of the file, with how much of each must arrive before page one appears.
Making the file smaller
The same document written twice, plainly and packed, with what each one weighs and what the packing saved.
A document that reads freely and asks not to be copied
A page that opens with nothing typed and prints like any other, and that asks the reading software to leave its text where it is. Every word of it is scrambled inside the file.
Fonts embedded in the file
Text set in a font embedded in the file, cut down to the letters actually used, and still searchable, copyable and readable aloud.
Letters you draw yourself
A tick, a cross and a dash drawn by the program, added to the document as a font, and set among ordinary words.