{
  "ca-prefix": "/example",
  "issuing-freshness": "720",
  "validity-period": "360",
  "ca-info": "An example NDNCERT CA",
  "probe": "[JSON attribute]:[JSON attribute]:[...] Example: email:UID"
  "supported-challenges":
  [
    { "type": "PIN" },
    { "type": "Email" }
  ]
}