{
  "properties": {
    "ssn": {
      "encrypt": {
        "keyId": [{
          "$binary": {
            "base64": "GCPAAAAAAAAAAAAAAAAAAA==",
            "subType": "04"
          }
        }],
        "bsonType": "string",
        "algorithm": "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic"
      }
    }
  },
  "bsonType": "object"
}