cmd/dht-secure-id/main.go | 34 ++++++++++++++++++++++++++++++++++

diff --git a/cmd/dht-secure-id/main.go b/cmd/dht-secure-id/main.go
new file mode 100644
index 0000000000000000000000000000000000000000..cf6c3a0851039c6f2bcd766e27c01d15f1663031
--- /dev/null
+++ b/cmd/dht-secure-id/main.go
@@ -0,0 +1,34 @@
+package main
+
+import (
+	"encoding/hex"
+	"fmt"
+	"net"
+	"os"
+
+	"github.com/docopt/docopt-go"
+
+	"github.com/anacrolix/torrent/dht"
+)
+
+func main() {
+	args, _ := docopt.Parse(`dht-secure-id outputs the node ID secured with the IP.
+
+Usage: dht-secure-id <id> <ip>`, nil, true, "", false)
+	id, err := hex.DecodeString(args["<id>"].(string))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "bad id: %s\n", err)
+		os.Exit(2)
+	}
+	if len(id) != 20 {
+		fmt.Fprintf(os.Stderr, "bad id: wrong length\n")
+		os.Exit(2)
+	}
+	ip := net.ParseIP(args["<ip>"].(string))
+	if ip == nil {
+		fmt.Fprintf(os.Stderr, "bad ip\n")
+		os.Exit(2)
+	}
+	dht.SecureNodeId(id, ip)
+	fmt.Printf("%x\n", id)
+}