diff --git a/back/genstring.go b/back/genstring.go
new file mode 100644
index 0000000..7cdf97c
--- /dev/null
+++ b/back/genstring.go
@@ -0,0 +1,27 @@
+package back
+
+import (
+	"bytes"
+	"crypto/rand"
+	"math/big"
+)
+
+var chars = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+
+func SecureGenString(length int) (string, error) {
+	charsLength := big.NewInt(int64(len(chars)))
+	var maxN big.Int
+	maxN.Exp(charsLength, big.NewInt(int64(length)), nil)
+	n, err := rand.Int(rand.Reader, &maxN)
+	if err != nil {
+		return "", err
+	}
+
+	var buf bytes.Buffer
+	for n.Cmp(&big.Int{}) == 1 {
+		var charIdx big.Int
+		n.DivMod(n, charsLength, &charIdx)
+		_ = buf.WriteByte(chars[charIdx.Int64()])
+	}
+	return buf.String(), nil
+}
diff --git a/store.go b/back/store.go
similarity index 99%
rename from store.go
rename to back/store.go
index c8e9402..b80a3ef 100644
--- a/store.go
+++ b/back/store.go
@@ -1,4 +1,4 @@
-package henwen
+package back
 
 import (
 	"context"
diff --git a/http/server.go b/front/server.go
similarity index 77%
rename from http/server.go
rename to front/server.go
index 1bd5cf0..8b7bff5 100644
--- a/http/server.go
+++ b/front/server.go
@@ -1,14 +1,9 @@
-package main
+package front
 
 import (
-	"bytes"
 	"context"
-	"crypto/rand"
-	"flag"
 	"fmt"
 	"io"
-	"log"
-	"math/big"
 	"net/http"
 	"net/url"
 	"time"
@@ -16,7 +11,7 @@ import (
 	hm "gitlab.codemonkeysoftware.net/b/hatmill"
 	a "gitlab.codemonkeysoftware.net/b/hatmill/attribute"
 	e "gitlab.codemonkeysoftware.net/b/hatmill/element"
-	"gitlab.codemonkeysoftware.net/b/henwen"
+	"gitlab.codemonkeysoftware.net/b/henwen/back"
 )
 
 const (
@@ -28,14 +23,14 @@ const (
 
 type handler struct {
 	mux     *http.ServeMux
-	store   *henwen.Store
+	store   *back.Store
 	title   string
 	baseURL string
 }
 
 type HandlerParams struct {
 	Title   string
-	Store   *henwen.Store
+	Store   *back.Store
 	BaseURL string
 }
 
@@ -103,7 +98,7 @@ func (h *handler) handleDoCreate(w http.ResponseWriter, r *http.Request) {
 	}
 	description := r.FormValue(fieldNameDescription)
 
-	event, err := h.store.CreateEvent(context.Background(), henwen.CreateEventCommand{
+	event, err := h.store.CreateEvent(context.Background(), back.CreateEventCommand{
 		Name:         eventName,
 		Description:  description,
 		EarliestDate: earliest,
@@ -145,7 +140,7 @@ func (h *handler) handleDoCreate(w http.ResponseWriter, r *http.Request) {
 
 func (h *handler) handleAdmin(w http.ResponseWriter, r *http.Request) {
 	query := r.URL.Query()
-	event, err := h.store.GetEvent(context.Background(), henwen.GetEventQuery{
+	event, err := h.store.GetEvent(context.Background(), back.GetEventQuery{
 		AlphaID:   query.Get(keyEventID),
 		AdminCode: query.Get(keyAdminCode),
 	})
@@ -218,47 +213,4 @@ const (
 const keyEventID = "event_id"
 const keyAdminCode = "admin_code"
 
-var chars = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
-
-func genString(length int) (string, error) {
-	charsLength := big.NewInt(int64(len(chars)))
-	var maxN big.Int
-	maxN.Exp(charsLength, big.NewInt(int64(length)), nil)
-	n, err := rand.Int(rand.Reader, &maxN)
-	if err != nil {
-		return "", err
-	}
-
-	var buf bytes.Buffer
-	for n.Cmp(&big.Int{}) == 1 {
-		var charIdx big.Int
-		n.DivMod(n, charsLength, &charIdx)
-		_ = buf.WriteByte(chars[charIdx.Int64()])
-	}
-	return buf.String(), nil
-}
-
 const formDateLayout = "2006-01-02"
-
-func main() {
-	addr := flag.String("address", ":8080", "bind address for HTTP server as host:port")
-	title := flag.String("title", "Henwen", "website title")
-	baseURL := flag.String("baseURL", "http://localhost:8080", "base URL for HTTP routes")
-	dbFileName := flag.String("db", "./henwen.db", "name of database file")
-	flag.Parse()
-
-	store, err := henwen.NewStore(*dbFileName, genString)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	srv := http.Server{
-		Addr: *addr,
-		Handler: NewHandler(HandlerParams{
-			Store:   store,
-			Title:   *title,
-			BaseURL: *baseURL,
-		}),
-	}
-	log.Println(srv.ListenAndServe())
-}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..8e9f0c8
--- /dev/null
+++ b/main.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"net/http"
+
+	"gitlab.codemonkeysoftware.net/b/henwen/back"
+	"gitlab.codemonkeysoftware.net/b/henwen/front"
+)
+
+func main() {
+	addr := flag.String("address", ":8080", "bind address for HTTP server as host:port")
+	title := flag.String("title", "Henwen", "website title")
+	baseURL := flag.String("baseURL", "http://localhost:8080", "base URL for HTTP routes")
+	dbFileName := flag.String("db", "./henwen.db", "name of database file")
+	flag.Parse()
+
+	store, err := back.NewStore(*dbFileName, back.SecureGenString)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	srv := http.Server{
+		Addr: *addr,
+		Handler: front.NewHandler(front.HandlerParams{
+			Store:   store,
+			Title:   *title,
+			BaseURL: *baseURL,
+		}),
+	}
+	log.Println(srv.ListenAndServe())
+}