SSH KeysGenerating, adding and using a key pair instead of a password.ComputingModern practice: ed25519 rather than RSA.1Generatessh-keygen -t ed25519 -C "you@example.com"2Use a passphraseIt encrypts the key on disk. The agent means you type it once persession.3Add to the agentssh-add ~/.ssh/id_ed255194Copy the PUBLIC keyThe .pub file. ssh-copy-id, or paste it into the service.5Testssh -T git@github.comFILESid_ed25519 — private, never shareid_ed25519.pub — public, safe to paste~/.ssh/config — per-host settingsPrivate keys need mode 600 and the .ssh directory 700. SSH refuses touse a key anyone else can read.SSH Keyslearnposters.com
SSH Keys — printable computing wall chart from LearnPosters. Free vector PDF, US Letter and A4.

SSH Keys, step by step

Modern practice: ed25519 rather than RSA.

  1. Generatessh-keygen -t ed25519 -C "you@example.com"
  2. Use a passphraseIt encrypts the key on disk. The agent means you type it once per session.
  3. Add to the agentssh-add ~/.ssh/id_ed25519
  4. Copy the PUBLIC keyThe .pub file. ssh-copy-id, or paste it into the service.
  5. Testssh -T git@github.com

Files

  • id_ed25519 — private, never share
  • id_ed25519.pub — public, safe to paste
  • ~/.ssh/config — per-host settings

Private keys need mode 600 and the .ssh directory 700. SSH refuses to use a key anyone else can read.

Questions about the SSH Keys poster

What’s on the SSH Keys poster?
5 numbered steps, with a full worked run-through. Modern practice: ed25519 rather than RSA. Generate — ssh-keygen -t ed25519 -C "you@example.com"; Use a passphrase — It encrypts the key on disk. The agent means you type it once per…; Add to the agent — ssh-add ~/.ssh/id_ed25519; Copy the PUBLIC key — The .pub file. ssh-copy-id, or paste it into the service.; Test — ssh -T git@github.com. Private keys need mode 600 and the .ssh directory 700. SSH refuses to use a key anyone else can read.
Who is the SSH Keys poster for?
SSH Keys belongs to the Computing section rather than to a school year, because computing is not something one grade owns. Anyone learning tools can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the SSH Keys poster?
The private key never leaves your machine. If it has, it is not private any more. A wall chart earns its place by being glanceable from where the work is happening, so SSH Keys belongs on the wall where that computing work actually happens, within glancing distance, rather than filed away.
What other posters go with SSH Keys?
Code Review, Debugging Method and Docker Basics sit alongside SSH Keys in the Computing section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Code ReviewDebugging MethodDocker Basics
Is the SSH Keys poster free to download and print?
Yes. SSH Keys downloads as a free PDF with no account, no email and no watermark, like everything else in the Computing section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the SSH Keys poster print at?
SSH Keys is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of SSH Keys loses nothing.Printing guide

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