diff --git a/go.sum b/go.sum
index 25affc6..85f0e8b 100644
--- a/go.sum
+++ b/go.sum
@@ -30,6 +30,7 @@ github.com/coreos/go-semver v0.3.0 h1:wkHLiw0WNATZnSG7epLsujiMCgPAc9xhjJ4tgnAxmf
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davidlazar/go-crypto v0.0.0-20170701192655-dcfb0a7ac018 h1:6xT9KW8zLC5IlbaIF5Q7JNieBoACT7iW0YTxQHR0in0=
 github.com/davidlazar/go-crypto v0.0.0-20170701192655-dcfb0a7ac018/go.mod h1:rQYf4tfk5sSwFsnDg3qYaBxSjsD9S8+59vW0dKUgme4=
@@ -265,6 +266,7 @@ github.com/pierrec/lz4 v2.0.5+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v0.9.2/go.mod h1:OsXs2jCmiKlQ1lTBmv21f2mNfw4xf/QclQDMrYNZzcM=
@@ -293,6 +295,7 @@ github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/syndtr/goleveldb v1.0.0/go.mod h1:ZVVdQEZoIme9iO1Ch2Jdy24qqXrMMOU6lpPAyBWyWuQ=
 github.com/whyrusleeping/base32 v0.0.0-20170828182744-c30ac30633cc h1:BCPnHtcboadS0DvysUuJXZ4lWVv5Bh5i7+tbIyi+ck4=
diff --git a/p2p.go b/p2p.go
index ea6961f..326333d 100644
--- a/p2p.go
+++ b/p2p.go
@@ -8,7 +8,7 @@ import (
 	"io"
 	"io/ioutil"
 	"math/rand"
-	"strings"
+	"os"
 	"time"
 
 	"github.com/pkg/errors"
@@ -302,8 +302,11 @@ func NewHost(ctx context.Context, options ...Option) (*Host, error) {
 
 	// private p2p network
 	if cfg.PrivateNetworkPSK != "" {
-		reader := strings.NewReader(cfg.PrivateNetworkPSK)
-		p, err := pnet.NewProtector(reader)
+		f, err := os.Open(cfg.PrivateNetworkPSK)
+		if err != nil {
+			return nil, err
+		}
+		p, err := pnet.NewProtector(f)
 		if err != nil {
 			return nil, err
 		}