gpg-overview.dot

digraph gpg {
        //----------------
        // Default settigs
        //----------------

        fontname="Bitstream Vera Sans"
        fontsize=8

        graph [
                nodesep=0.5
                ranksep=1.5
                ordering=out
        ]

        node [
                shape=record
                style=filled
                color=white
        ]

        edge [
                arrowhead=vee
                labeldistance=1.5
        ]

        {
                node [
                      style=solid
                      color=black
                ]

                "gpg"
                "private keyring"
                "public keyring"
        }

        "private key" -> "public key" [arrowhead=none, label="same hash as", constraint=false]
        "private key" -> "private keyring" [arrowhead=diamond, taillabel="*", headlabel="*", constraint=false]
        "public key" -> "public keyring" [arrowhead=diamond, taillabel="*", headlabel="*", constraint=false]
        "gpg" -> "public keyring" [label="operates on"]
        "gpg" -> "private keyring" [label="operates on"]

        //
        // Private key sub-graph
        //

        subgraph cluster_private {
                style=filled
                color=tomato

                // Nodes

                "private key" [label="{private key|+ hash : Key fingerprint\l}"]
                "key data to private key" [label="", fixedsize="false", width=0, height=0, shape=none]
                "private key to smart card" [label="", fixedsize="false", width=0, height=0, shape=none]
                "smart card" [label="{smart card|+ serial : Smart card serial number\l}"]
                "private key data" [label="key data"]

                // Relations

                "private key data" -> "key data to private key" [arrowhead=none, taillabel="1"]
                "key data to private key" -> "private key" [arrowhead=diamond, headlabel="1"]
                "private key" -> "private key to smart card" [arrowhead=none, taillabel="1"]
                "private key to smart card" -> "smart card" [headlabel="1"]
                "key data to private key" -> "private key to smart card" [arrowhead=none, style=dashed, label="{xor}"]

                { rank=same; "private key data" "smart card" }
                { rank=same; "private key to smart card" "key data to private key" }
        }

        //
        // Public key sub-graph
        //

        subgraph cluster_public {
                style=filled
                color=lightblue

                // Nodes

                "public key" [label="{public key|+ hash : Key fingerprint\l+ created : Date created\l+ expires : Expiration date\l+ usage : One or more of certify, sign, encrypt and authenticate\l}"]
                "signature" [label="{signature|+ hash : Hash of key that signed the uid\l+ policy : URL to policy description\l+ notation : Notation text\l}"]
                "public key data" [label="key data"]

                // Relations

                "sub-key" -> "master key" [arrowhead=diamond, taillabel="*", headlabel="1"]
                "uid" -> "master key" [arrowhead=diamond, taillabel="*", headlabel="1"]
                "signature" -> "uid" [arrowhead=diamond, taillabel="*", headlabel="1"]
                "master key" -> "public key" [arrowhead=onormal]
                "sub-key" -> "public key" [arrowhead=onormal]
                "e-mail uid" -> "uid" [arrowhead=onormal]
                "photo uid" -> "uid" [arrowhead=onormal]
                "public key" -> "keyserver" [arrowhead=diamond, label="stores", taillabel="*", headlabel="*"]
                "public key data" -> "public key" [arrowhead=diamond, taillabel="1", headlabel="1"]
        }
}