diff --git a/cmd/fdroidcl/main.go b/cmd/fdroidcl/main.go
index a4d0611..db74de1 100644
--- a/cmd/fdroidcl/main.go
+++ b/cmd/fdroidcl/main.go
@@ -4,6 +4,7 @@
 package main
 
 import (
+	"encoding/hex"
 	"flag"
 	"fmt"
 	"log"
@@ -147,11 +148,9 @@ func printAppDetailed(app fdroidcl.App) {
 	}
 }
 
-var repoURL = flag.String("r", "https://f-droid.org/repo", "repository address")
-
 func init() {
 	flag.Usage = func() {
-		fmt.Fprintln(os.Stderr, "Usage: fdroidcl [-h] [-r <repo address>] <command> [<args>]")
+		fmt.Fprintln(os.Stderr, "Usage: fdroidcl [-h] <command> [<args>]")
 		fmt.Fprintln(os.Stderr)
 		fmt.Fprintln(os.Stderr, "Available commands:")
 		fmt.Fprintln(os.Stderr, "   update             Update the index")
@@ -171,7 +170,7 @@ func appSubdir(appdir string) string {
 	return p
 }
 
-func indexPath(repoName string) string {
+func indexPath(name string) string {
 	cache, err := appdir.Cache()
 	if err != nil {
 		log.Fatalf("Could not determine cache dir: %v", err)
@@ -179,7 +178,7 @@ func indexPath(repoName string) string {
 	return filepath.Join(appSubdir(cache), repoName+".jar")
 }
 
-func updateIndex(repoName, repoURL string) error {
+func updateIndex() error {
 	p := indexPath(repoName)
 	url := fmt.Sprintf("%s/%s", repoURL, "index.jar")
 	if err := downloadEtag(url, p); err != nil {
@@ -188,7 +187,7 @@ func updateIndex(repoName, repoURL string) error {
 	return nil
 }
 
-func mustLoadIndex(repoName string) *fdroidcl.Index {
+func mustLoadIndex() *fdroidcl.Index {
 	p := indexPath(repoName)
 	f, err := os.Open(p)
 	if err != nil {
@@ -198,7 +197,11 @@ func mustLoadIndex(repoName string) *fdroidcl.Index {
 	if err != nil {
 		log.Fatalf("Could not stat index file: %v", err)
 	}
-	index, err := fdroidcl.LoadIndexJar(f, stat.Size())
+	pubkey, err := hex.DecodeString(repoPubkey)
+	if err != nil {
+		log.Fatalf("Could not decode public key: %v", err)
+	}
+	index, err := fdroidcl.LoadIndexJar(f, stat.Size(), pubkey)
 	if err != nil {
 		log.Fatalf("Could not load index: %v", err)
 	}
@@ -247,25 +250,23 @@ func main() {
 	cmd := flag.Args()[0]
 	args := flag.Args()[1:]
 
-	repoName := "index"
-
 	switch cmd {
 	case "update":
-		err := updateIndex(repoName, *repoURL)
+		err := updateIndex()
 		if err == errNotModified {
 			log.Print("Index up to date")
 		} else if err != nil {
 			log.Fatalf("Could not update index: %v", err)
 		}
 	case "list":
-		index := mustLoadIndex(repoName)
+		index := mustLoadIndex()
 		printApps(index.Apps)
 	case "search":
-		index := mustLoadIndex(repoName)
+		index := mustLoadIndex()
 		apps := filterAppsSearch(index.Apps, args)
 		printApps(apps)
 	case "show":
-		index := mustLoadIndex(repoName)
+		index := mustLoadIndex()
 		found := make(map[string]*fdroidcl.App, len(args))
 		for _, appID := range args {
 			found[appID] = nil
@@ -298,7 +299,7 @@ func main() {
 			fmt.Printf("%s - %s (%s)\n", device.Id, device.Model, device.Product)
 		}
 	case "installed":
-		index := mustLoadIndex(repoName)
+		index := mustLoadIndex()
 		startAdbIfNeeded()
 		device := oneDevice()
 		installed := mustInstalled(device)
diff --git a/cmd/fdroidcl/repo.go b/cmd/fdroidcl/repo.go
new file mode 100644
index 0000000..7da065d
--- /dev/null
+++ b/cmd/fdroidcl/repo.go
@@ -0,0 +1,10 @@
+/* Copyright (c) 2015, Daniel Martí <mvdan@mvdan.cc> */
+/* See LICENSE for licensing information */
+
+package main
+
+const (
+	repoName   = "repo"
+	repoURL    = "https://f-droid.org/repo"
+	repoPubkey = "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"
+)
diff --git a/jar.go b/jar.go
index b22cde9..4722578 100644
--- a/jar.go
+++ b/jar.go
@@ -5,8 +5,10 @@ package fdroidcl
 
 import (
 	"archive/zip"
+	//"crypto/x509"
 	"errors"
 	"io"
+	//"io/ioutil"
 	"regexp"
 )
 
@@ -20,11 +22,22 @@ var (
 	ErrTooManySigs = errors.New("multiple jar signatures found")
 )
 
-func verifySignature(sig io.Reader) error {
-	return nil
+func verifySignature(pubkey []byte, sig io.Reader) error {
+	/*
+	sigBytes, err := ioutil.ReadAll(sig)
+	if err != nil {
+		return err
+	}
+	cert, err := x509.ParseCertificate(pubkey)
+	if err != nil {
+		return err
+	}
+	return cert.CheckSignature(x509.MD5WithRSA, ...)
+	*/
+	return nil // MD5WithRSA is currently unimplemented
 }
 
-func LoadIndexJar(r io.ReaderAt, size int64) (*Index, error) {
+func LoadIndexJar(r io.ReaderAt, size int64, pubkey []byte) (*Index, error) {
 	reader, err := zip.NewReader(r, size)
 	if err != nil {
 		return nil, err
@@ -55,7 +68,7 @@ func LoadIndexJar(r io.ReaderAt, size int64) (*Index, error) {
 		return nil, ErrNoSigs
 	}
 	defer sig.Close()
-	if err := verifySignature(sig); err != nil {
+	if err := verifySignature(pubkey, sig); err != nil {
 		return nil, err
 	}
 	return LoadIndexXml(index)