diff --git a/cmd/cmd.go b/cmd/cmd.go
index 7255ead..759cb73 100644
--- a/cmd/cmd.go
+++ b/cmd/cmd.go
@@ -274,7 +274,7 @@ var globalFlags = []cli.Flag{
 		Value:  "",
 		EnvVar: "CORS_DOMAINS",
 	},
-	cli.Int64Flag{
+	cli.IntFlag{
 		Name:   "random-token-length",
 		Usage:  "",
 		Value:  6,
@@ -383,7 +383,7 @@ func New() *Cmd {
 			options = append(options, server.RateLimit(v))
 		}
 
-		v := c.Int64("random-token-length")
+		v := c.Int("random-token-length")
 		options = append(options, server.RandomTokenLength(v))
 
 		purgeDays := c.Int("purge-days")
diff --git a/server/codec.go b/server/codec.go
index a33f3c0..1ede6a9 100644
--- a/server/codec.go
+++ b/server/codec.go
@@ -36,28 +36,14 @@ const (
 
 	// someone set us up the bomb !!
 	BASE = float64(len(SYMBOLS))
-
-	// init seed encode number
-	INIT_SEED = float64(-1)
 )
 
-// encodes a number into our *base* representation
-// TODO can this be made better with some bitshifting?
-func Encode(number float64, length int64) string {
-	if number == INIT_SEED {
-		seed := math.Pow(float64(BASE), float64(length))
-		number = seed + (rand.Float64() * seed) // start with seed to enforce desired length
-	}
-
-	rest := int64(math.Mod(number, BASE))
-	// strings are a bit weird in go...
-	result := string(SYMBOLS[rest])
-	if rest > 0 && number-float64(rest) != 0 {
-		newnumber := (number - float64(rest)) / BASE
-		result = Encode(newnumber, length) + result
-	} else {
-		// it would always be 1 because of starting with seed and we want to skip
-		return ""
+// generate a token
+func Token(length int) string {
+	result := ""
+	for i := 0; i < length; i++ {
+		x := rand.Intn(len(SYMBOLS))
+		result = string(SYMBOLS[x]) + result
 	}
 
 	return result
diff --git a/server/codec_test.go b/server/codec_test.go
index aebd8ab..5ee1db2 100644
--- a/server/codec_test.go
+++ b/server/codec_test.go
@@ -4,12 +4,12 @@ import "testing"
 
 func BenchmarkEncodeConcat(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		_ = Encode(INIT_SEED, 5) + Encode(INIT_SEED, 5)
+		_ = Token(5) + Token(5)
 	}
 }
 
 func BenchmarkEncodeLonger(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		_ = Encode(INIT_SEED, 10)
+		_ = Token(10)
 	}
 }
diff --git a/server/handlers.go b/server/handlers.go
index ac20a0f..37b6fed 100644
--- a/server/handlers.go
+++ b/server/handlers.go
@@ -276,7 +276,7 @@ func (s *Server) postHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	token := Encode(INIT_SEED, s.randomTokenLength)
+	token := Token(s.randomTokenLength)
 
 	w.Header().Set("Content-Type", "text/plain")
 
@@ -398,13 +398,13 @@ type Metadata struct {
 	DeletionToken string
 }
 
-func MetadataForRequest(contentType string, randomTokenLength int64, r *http.Request) Metadata {
+func MetadataForRequest(contentType string, randomTokenLength int, r *http.Request) Metadata {
 	metadata := Metadata{
 		ContentType:   strings.ToLower(contentType),
 		MaxDate:       time.Time{},
 		Downloads:     0,
 		MaxDownloads:  -1,
-		DeletionToken: Encode(INIT_SEED, randomTokenLength) + Encode(INIT_SEED, randomTokenLength),
+		DeletionToken: Token(randomTokenLength) + Token(randomTokenLength),
 	}
 
 	if v := r.Header.Get("Max-Downloads"); v == "" {
@@ -492,7 +492,7 @@ func (s *Server) putHandler(w http.ResponseWriter, r *http.Request) {
 
 	contentType := mime.TypeByExtension(filepath.Ext(vars["filename"]))
 
-	token := Encode(INIT_SEED, s.randomTokenLength)
+	token := Token(s.randomTokenLength)
 
 	metadata := MetadataForRequest(contentType, s.randomTokenLength, r)
 
@@ -636,23 +636,22 @@ func (metadata Metadata) remainingLimitHeaderValues() (remainingDownloads, remai
 	return remainingDownloads, remainingDays
 }
 
-func (s *Server) Lock(token, filename string) error {
+func (s *Server) Lock(token, filename string) {
 	key := path.Join(token, filename)
 
-	if _, ok := s.locks[key]; !ok {
-		s.locks[key] = &sync.Mutex{}
-	}
+	lock, _ := s.locks.LoadOrStore(key, &sync.Mutex{})
 
-	s.locks[key].Lock()
+	lock.(*sync.Mutex).Lock()
 
-	return nil
+	return
 }
 
-func (s *Server) Unlock(token, filename string) error {
+func (s *Server) Unlock(token, filename string)  {
 	key := path.Join(token, filename)
-	s.locks[key].Unlock()
 
-	return nil
+	lock, _ := s.locks.LoadOrStore(key, &sync.Mutex{})
+
+	lock.(*sync.Mutex).Unlock()
 }
 
 func (s *Server) CheckMetadata(token, filename string, increaseDownload bool) (Metadata, error) {
diff --git a/server/server.go b/server/server.go
index cf72989..ea0a0de 100644
--- a/server/server.go
+++ b/server/server.go
@@ -187,7 +187,7 @@ func RateLimit(requests int) OptionFn {
 	}
 }
 
-func RandomTokenLength(length int64) OptionFn {
+func RandomTokenLength(length int) OptionFn {
 	return func(srvr *Server) {
 		srvr.randomTokenLength = length
 	}
@@ -288,7 +288,7 @@ type Server struct {
 
 	profilerEnabled bool
 
-	locks map[string]*sync.Mutex
+	locks sync.Map
 
 	maxUploadSize     int64
 	rateLimitRequests int
@@ -300,7 +300,7 @@ type Server struct {
 
 	forceHTTPs bool
 
-	randomTokenLength int64
+	randomTokenLength int
 
 	ipFilterOptions *IPFilterOptions
 
@@ -329,7 +329,7 @@ type Server struct {
 
 func New(options ...OptionFn) (*Server, error) {
 	s := &Server{
-		locks: map[string]*sync.Mutex{},
+		locks: sync.Map{},
 	}
 
 	for _, optionFn := range options {