Add information on keypairs

README.md

@@ -106,3 +106,16 @@ To become an institution admin in invite, add the following values as `eduPerson
 ### [Technical documentation](#technical-documentation)
 
 <https://openconext.github.io/OpenConext-Invite/>
+
+### Provisioning Secrets 
+The secrets (passwords / API-keys) used in provisionings are encrypted in OpenConext-Manage using keypairs.
+
+#### Create private / public keypair
+```
+openssl genrsa -traditional -out private_key.pem 2048
+openssl rsa -pubout -in private_key.pem -out public_key.pem
+```
+#### Convert private key to pkcs8 format in order to import it from Java
+```
+openssl pkcs8 -topk8 -in private_key.pem -inform pem -out private_key_pkcs8.pem -outform pem -nocrypt
+```