diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c5d708..d096970 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,10 +7,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 ### Security
 - Updated underlying crypto library
+- Improved memory zeroing in helpers
 
 ### Fixed
 - Fixed test `TestMultipleKeyMessageEncryption`
 - Fixed garbage collection issues when compiled on gomobile, by copying byte slices
+- Password encrypted binary files now have the correct flags
+- Fixed missing space in `Hash` header of cleartext messages
+
+## Changed
+- Providing empty passphrase does no longer throw an error when unlocking an unencrypted private key
 
 ### Added
 - SHA256 fingerprint support
diff --git a/constants/armor.go b/constants/armor.go
index ac20ea9..28db229 100644
--- a/constants/armor.go
+++ b/constants/armor.go
@@ -3,7 +3,7 @@ package constants
 
 // Constants for armored data.
 const (
-	ArmorHeaderVersion = "GopenPGP 0.0.1 (" + Version + ")"
+	ArmorHeaderVersion = "GopenPGP 2.0.0"
 	ArmorHeaderComment = "https://gopenpgp.org"
 	PGPMessageHeader   = "PGP MESSAGE"
 	PGPSignatureHeader = "PGP SIGNATURE"
diff --git a/crypto/key.go b/crypto/key.go
index 106c33f..349bed4 100644
--- a/crypto/key.go
+++ b/crypto/key.go
@@ -104,6 +104,10 @@ func (key *Key) Lock(passphrase []byte) (*Key, error) {
 		return nil, err
 	}
 
+	if passphrase == nil {
+		return lockedKey, nil
+	}
+
 	err = lockedKey.entity.PrivateKey.Encrypt(passphrase)
 	if err != nil {
 		return nil, errors.Wrap(err, "gopenpgp: error in locking key")
@@ -136,6 +140,9 @@ func (key *Key) Unlock(passphrase []byte) (*Key, error) {
 	}
 
 	if !isLocked {
+		if passphrase == nil {
+			return key.Copy()
+		}
 		return nil, errors.New("gopenpgp: key is not locked")
 	}
 
diff --git a/crypto/message.go b/crypto/message.go
index b2cc259..10ab8a4 100644
--- a/crypto/message.go
+++ b/crypto/message.go
@@ -366,7 +366,7 @@ func (msg *ClearTextMessage) GetArmored() (string, error) {
 		return "", err
 	}
 
-	str := "-----BEGIN PGP SIGNED MESSAGE-----\r\nHash:SHA512\r\n\r\n"
+	str := "-----BEGIN PGP SIGNED MESSAGE-----\r\nHash: SHA512\r\n\r\n"
 	str += msg.GetString()
 	str += "\r\n"
 	str += armSignature
diff --git a/crypto/password.go b/crypto/password.go
index 8230626..ea718b6 100644
--- a/crypto/password.go
+++ b/crypto/password.go
@@ -15,7 +15,7 @@ import (
 // * password: A password that will be derived into an encryption key
 // * output  : The encrypted data as PGPMessage
 func EncryptMessageWithPassword(message *PlainMessage, password []byte) (*PGPMessage, error) {
-	encrypted, err := passwordEncrypt(message.GetBinary(), password)
+	encrypted, err := passwordEncrypt(message.GetBinary(), password, message.IsBinary())
 	if err != nil {
 		return nil, err
 	}
@@ -99,14 +99,16 @@ func EncryptSessionKeyWithPassword(sk *SessionKey, password []byte) ([]byte, err
 
 // ----- INTERNAL FUNCTIONS ------
 
-func passwordEncrypt(message []byte, password []byte) ([]byte, error) {
+func passwordEncrypt(message []byte, password []byte, isBinary bool) ([]byte, error) {
 	var outBuf bytes.Buffer
 
 	config := &packet.Config{
 		Time: getTimeGenerator(),
 	}
 
-	encryptWriter, err := openpgp.SymmetricallyEncrypt(&outBuf, password, nil, config)
+	hints := &openpgp.FileHints{IsBinary: isBinary}
+
+	encryptWriter, err := openpgp.SymmetricallyEncrypt(&outBuf, password, hints, config)
 	if err != nil {
 		return nil, err
 	}
diff --git a/helper/cleartext.go b/helper/cleartext.go
index 1eab67c..a8c07e5 100644
--- a/helper/cleartext.go
+++ b/helper/cleartext.go
@@ -19,6 +19,7 @@ func SignCleartextMessageArmored(privateKey string, passphrase []byte, text stri
 	if err != nil {
 		return "", err
 	}
+	defer unlockedKey.ClearPrivateParams()
 
 	keyRing, err := crypto.NewKeyRing(unlockedKey)
 	if err != nil {
diff --git a/helper/helper.go b/helper/helper.go
index c232eb1..892f975 100644
--- a/helper/helper.go
+++ b/helper/helper.go
@@ -94,6 +94,7 @@ func EncryptSignMessageArmored(
 	if unlockedKeyObj, err = privateKeyObj.Unlock(passphrase); err != nil {
 		return "", err
 	}
+	defer unlockedKeyObj.ClearPrivateParams()
 
 	if privateKeyRing, err = crypto.NewKeyRing(unlockedKeyObj); err != nil {
 		return "", err
@@ -126,6 +127,7 @@ func DecryptMessageArmored(
 	if privateKeyUnlocked, err = privateKeyObj.Unlock(passphrase); err != nil {
 		return "", err
 	}
+	defer privateKeyUnlocked.ClearPrivateParams()
 
 	if privateKeyRing, err = crypto.NewKeyRing(privateKeyUnlocked); err != nil {
 		return "", err
@@ -168,6 +170,7 @@ func DecryptVerifyMessageArmored(
 	if unlockedKeyObj, err = privateKeyObj.Unlock(passphrase); err != nil {
 		return "", err
 	}
+	defer unlockedKeyObj.ClearPrivateParams()
 
 	if privateKeyRing, err = crypto.NewKeyRing(unlockedKeyObj); err != nil {
 		return "", err
@@ -214,6 +217,7 @@ func DecryptVerifyAttachment(
 	if unlockedKeyObj, err = privateKeyObj.Unlock(passphrase); err != nil {
 		return nil, err
 	}
+	defer unlockedKeyObj.ClearPrivateParams()
 
 	if privateKeyRing, err = crypto.NewKeyRing(unlockedKeyObj); err != nil {
 		return nil, err
diff --git a/helper/key.go b/helper/key.go
index a1a695b..1ef0a8a 100644
--- a/helper/key.go
+++ b/helper/key.go
@@ -19,13 +19,13 @@ func UpdatePrivateKeyPassphrase(
 	if err != nil {
 		return "", err
 	}
+	defer unlocked.ClearPrivateParams()
 
 	locked, err := unlocked.Lock(newPassphrase)
 	if err != nil {
 		return "", err
 	}
 
-	unlocked.ClearPrivateParams()
 	return locked.Armor()
 }
 
@@ -37,13 +37,13 @@ func GenerateKey(name, email string, passphrase []byte, keyType string, bits int
 	if err != nil {
 		return "", err
 	}
+	defer key.ClearPrivateParams()
 
 	locked, err := key.Lock(passphrase)
 	if err != nil {
 		return "", err
 	}
 
-	key.ClearPrivateParams()
 	return locked.Armor()
 }
 
diff --git a/helper/sign_attachment.go b/helper/sign_attachment.go
index 2cb0003..c5b413b 100644
--- a/helper/sign_attachment.go
+++ b/helper/sign_attachment.go
@@ -33,6 +33,7 @@ func EncryptSignAttachment(
 	if unlockedKeyObj, err = privateKeyObj.Unlock(passphrase); err != nil {
 		return nil, nil, nil, err
 	}
+	defer unlockedKeyObj.ClearPrivateParams()
 
 	if privateKeyRing, err = crypto.NewKeyRing(unlockedKeyObj); err != nil {
 		return nil, nil, nil, err