Internet Protocol security (IPsec) can use preshared keys for authentication. Preshared means that the parties agree on a shared, secret key that is used for authentication. Note that the preshared key is only used for authentication. The IPsec session key that is used to encrypt data sent between the IPsec peers is generated by a Diffie-Hellman key exchange.

Generate a 256-bit string for an IPsec preshared key

  1. Open the Random String Generator web page ( with your browser.
  2. In random strings, type 1.
  3. In objects in length, type 32.
  4. Click Generate random strings.
  5. Select the generated random string and copy it to your clipboard (Ctrl-C for Windows).
  6. Paste the content of your clipboard into the location where the pre-shared key should go (Ctrl-V for Windows).
  7. For additional random strings, start at step 4.