diff --git a/CHANGELOG.md b/CHANGELOG.md
index fce7d6ee3..6629c56a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -317,6 +317,14 @@ BUG FIXES
 - [cmd] Set GenesisTime during `tendermint init`
 - [consensus] fix ValidBlock rules
 
+## 0.20.0 (TBD)
+
+BREAKING:
+
+- [p2p] Change the key/nonce derivation in secret connection to use hkdf instead of a raw hash function.
+
+
+
 ## 0.19.2 (April 30th, 2018)
 
 FEATURES:
diff --git a/Gopkg.lock b/Gopkg.lock
index 676751f14..796d81752 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -143,6 +143,7 @@
     ".",
     "hcl/ast",
     "hcl/parser",
+    "hcl/printer",
     "hcl/scanner",
     "hcl/strconv",
     "hcl/token",
@@ -194,11 +195,9 @@
 
 [[projects]]
   branch = "master"
-  digest = "1:5ab79470a1d0fb19b041a624415612f8236b3c06070161a910562f2b2d064355"
   name = "github.com/mitchellh/mapstructure"
   packages = ["."]
-  pruneopts = "UT"
-  revision = "f15292f7a699fcc1a38a80977f80a046874ba8ac"
+  revision = "bb74f1db0675b241733089d5a1faa5dd8b0ef57b"
 
 [[projects]]
   digest = "1:95741de3af260a92cc5c7f3f3061e85273f5a81b5db20d4bd68da74bd521675e"
@@ -382,13 +381,8 @@
   digest = "1:df132ec33d5acb4a1ab58d637f1bc3557be49456ca59b9198f5c1e7fa32e0d31"
   name = "golang.org/x/crypto"
   packages = [
-    "bcrypt",
-    "blowfish",
-    "chacha20poly1305",
     "curve25519",
     "hkdf",
-    "internal/chacha20",
-    "internal/subtle",
     "nacl/box",
     "nacl/secretbox",
     "openpgp/armor",
@@ -463,25 +457,17 @@
   packages = [
     ".",
     "balancer",
-    "balancer/base",
-    "balancer/roundrobin",
     "codes",
     "connectivity",
     "credentials",
-    "encoding",
-    "encoding/proto",
+    "grpclb/grpc_lb_v1/messages",
     "grpclog",
     "internal",
-    "internal/backoff",
-    "internal/channelz",
-    "internal/grpcrand",
     "keepalive",
     "metadata",
     "naming",
     "peer",
     "resolver",
-    "resolver/dns",
-    "resolver/passthrough",
     "stats",
     "status",
     "tap",
diff --git a/p2p/conn/secret_connection.go b/p2p/conn/secret_connection.go
index a2cbe008d..7762515d5 100644
--- a/p2p/conn/secret_connection.go
+++ b/p2p/conn/secret_connection.go
@@ -17,18 +17,16 @@ import (
 	"time"
 
 	"golang.org/x/crypto/nacl/box"
-	"golang.org/x/crypto/nacl/secretbox"
-	"golang.org/x/crypto/ripemd160"
 
 	"github.com/tendermint/tendermint/crypto"
 	cmn "github.com/tendermint/tendermint/libs/common"
+	"golang.org/x/crypto/hkdf"
 )
 
 // 4 + 1024 == 1028 total frame size
 const dataLenSize = 4
 const dataMaxSize = 1024
 const totalFrameSize = dataMaxSize + dataLenSize
-const sealedFrameSize = totalFrameSize + secretbox.Overhead
 
 // Implements net.Conn
 type SecretConnection struct {
@@ -124,14 +122,18 @@ func (sc *SecretConnection) Write(data []byte) (n int, err error) {
 		binary.BigEndian.PutUint32(frame, uint32(chunkLength))
 		copy(frame[dataLenSize:], chunk)
 
+		aead, err := xchacha20poly1305.New(sc.shrSecret[:])
+		if err != nil {
+			return n, errors.New("Invalid SecretConnection Key")
+		}
 		// encrypt the frame
-		var sealedFrame = make([]byte, sealedFrameSize)
-		secretbox.Seal(sealedFrame[:0], frame, sc.sendNonce, sc.shrSecret)
+		var sealedFrame = make([]byte, aead.Overhead()+totalFrameSize)
+		aead.Seal(sealedFrame[:0], sc.sendNonce[:], frame, nil)
 		// fmt.Printf("secretbox.Seal(sealed:%X,sendNonce:%X,shrSecret:%X\n", sealedFrame, sc.sendNonce, sc.shrSecret)
 		incr2Nonce(sc.sendNonce)
 		// end encryption
 
-		_, err := sc.conn.Write(sealedFrame)
+		_, err = sc.conn.Write(sealedFrame)
 		if err != nil {
 			return n, err
 		}
@@ -148,7 +150,11 @@ func (sc *SecretConnection) Read(data []byte) (n int, err error) {
 		return
 	}
 
-	sealedFrame := make([]byte, sealedFrameSize)
+	aead, err := xchacha20poly1305.New(sc.shrSecret[:])
+	if err != nil {
+		return n, errors.New("Invalid SecretConnection Key")
+	}
+	sealedFrame := make([]byte, totalFrameSize+aead.Overhead())
 	_, err = io.ReadFull(sc.conn, sealedFrame)
 	if err != nil {
 		return
@@ -157,8 +163,8 @@ func (sc *SecretConnection) Read(data []byte) (n int, err error) {
 	// decrypt the frame
 	var frame = make([]byte, totalFrameSize)
 	// fmt.Printf("secretbox.Open(sealed:%X,recvNonce:%X,shrSecret:%X\n", sealedFrame, sc.recvNonce, sc.shrSecret)
-	_, ok := secretbox.Open(frame[:0], sealedFrame, sc.recvNonce, sc.shrSecret)
-	if !ok {
+	_, err = aead.Open(frame[:0], sc.recvNonce[:], sealedFrame, nil)
+	if err != nil {
 		return n, errors.New("Failed to decrypt SecretConnection")
 	}
 	incr2Nonce(sc.recvNonce)
@@ -317,22 +323,19 @@ func shareAuthSignature(sc *SecretConnection, pubKey crypto.PubKey, signature cr
 
 // sha256
 func hash32(input []byte) (res *[32]byte) {
-	hasher := sha256.New()
-	hasher.Write(input) // nolint: errcheck, gas
-	resSlice := hasher.Sum(nil)
+	hash := sha256.New
+	hkdf := hkdf.New(hash, input, nil, []byte("TENDERMINT_SECRET_CONNECTION_KEY_GEN"))
 	res = new([32]byte)
-	copy(res[:], resSlice)
-	return
+	io.ReadFull(hkdf, res[:])
+	return res
 }
 
-// We only fill in the first 20 bytes with ripemd160
 func hash24(input []byte) (res *[24]byte) {
-	hasher := ripemd160.New()
-	hasher.Write(input) // nolint: errcheck, gas
-	resSlice := hasher.Sum(nil)
+	hash := sha256.New
+	hkdf := hkdf.New(hash, input, nil, []byte("TENDERMINT_SECRET_CONNECTION_NONCE_GEN"))
 	res = new([24]byte)
-	copy(res[:], resSlice)
-	return
+	io.ReadFull(hkdf, res[:])
+	return res
 }
 
 // increment nonce big-endian by 2 with wraparound.