+-----+                            +--------+
   | KTA |                            | PKI TA |
   +-----+                            +--------+
      |                                   |
      | Signs                             | Signs
      |                                   |
      +-------------+                     V
      |             |                   +----+
      V             V                   | CA |
   +-----+       +-----+                +----+
   | KSA |       | KDA |                   |
   +-----+       +-----+                   | Signs
      |           |                        |
      | Signs &   | Optionally             +---------------+
      | Encrypts  | Signs                  |               |
      |           |                        V               V
      |           |                +-------------+ +-------------+
      |           V                | Certificate | | Certificate |
  +---|-------------+              +-------------+ | Revocation  |
  |   V             | CMS Content                  | List        |
  | +-------------+ | Types                        +-------------+
  | | Key Package | |
  | +-------------+ |
  +-----------------+