diff --git a/core/core.go b/core/core.go
index a8b16da..965c4d6 100644
--- a/core/core.go
+++ b/core/core.go
@@ -94,6 +94,7 @@ type SummaryData struct {
 
 type DecryptWithDelegates struct {
 	Data      []byte
+	Secure    bool
 	Delegates []string
 }
 
@@ -299,7 +300,7 @@ func Decrypt(jsonIn []byte) ([]byte, error) {
 		return jsonStatusError(err)
 	}
 
-	data, names, err := crypt.Decrypt(s.Data, s.Name)
+	data, names, secure, err := crypt.Decrypt(s.Data, s.Name)
 	if err != nil {
 		log.Println("Error decrypting:", err)
 		return jsonStatusError(err)
@@ -307,6 +308,7 @@ func Decrypt(jsonIn []byte) ([]byte, error) {
 
 	resp := &DecryptWithDelegates{
 		Data:      data,
+		Secure:    secure,
 		Delegates: names,
 	}
 
diff --git a/cryptor/cryptor.go b/cryptor/cryptor.go
index 6978865..ea316d7 100644
--- a/cryptor/cryptor.go
+++ b/cryptor/cryptor.go
@@ -53,11 +53,11 @@ type SingleWrappedKey struct {
 // keys necessary to decrypt it when delegated.
 type EncryptedData struct {
 	Version   int
-	VaultId   int
-	Labels    []string
-	KeySet    []MultiWrappedKey
-	KeySetRSA map[string]SingleWrappedKey
-	IV        []byte
+	VaultId   int                         `json:",omitempty"`
+	Labels    []string                    `json:",omitempty"`
+	KeySet    []MultiWrappedKey           `json:",omitempty"`
+	KeySetRSA map[string]SingleWrappedKey `json:",omitempty"`
+	IV        []byte                      `json:",omitempty"`
 	Data      []byte
 	Signature []byte
 }
@@ -141,6 +141,42 @@ func (encrypted *EncryptedData) computeHmac(key []byte) []byte {
 	return mac.Sum(nil)
 }
 
+func (encrypted *EncryptedData) lock(key []byte) (err error) {
+	payload, err := json.Marshal(encrypted)
+	if err != nil {
+		return
+	}
+
+	mac := hmac.New(sha1.New, key)
+	mac.Write(payload)
+	sig := mac.Sum(nil)
+
+	*encrypted = EncryptedData{
+		Version:   -1,
+		Data:      payload,
+		Signature: sig,
+	}
+
+	return
+}
+
+func (encrypted *EncryptedData) unlock(key []byte) (err error) {
+	if encrypted.Version != -1 {
+		return
+	}
+
+	mac := hmac.New(sha1.New, key)
+	mac.Write(encrypted.Data)
+	sig := mac.Sum(nil)
+
+	if !hmac.Equal(encrypted.Signature, sig) {
+		err = errors.New("Signature mismatch")
+		return
+	}
+
+	return json.Unmarshal(encrypted.Data, encrypted)
+}
+
 // wrapKey encrypts the clear key such that a minimum number of delegated keys
 // are required to decrypt.  NOTE:  Currently the max value for min is 2.
 func (encrypted *EncryptedData) wrapKey(records *passvault.Records, clearKey []byte, names []string, min int) (err error) {
@@ -298,35 +334,44 @@ func (c *Cryptor) Encrypt(in []byte, labels, names []string, min int) (resp []by
 		return
 	}
 	encrypted.Signature = encrypted.computeHmac(hmacKey)
+	encrypted.lock(hmacKey)
 
 	return json.Marshal(encrypted)
 }
 
 // Decrypt decrypts a file using the keys in the key cache.
-func (c *Cryptor) Decrypt(in []byte, user string) (resp []byte, names []string, err error) {
+func (c *Cryptor) Decrypt(in []byte, user string) (resp []byte, names []string, secure bool, err error) {
 	// unwrap encrypted file
 	var encrypted EncryptedData
 	if err = json.Unmarshal(in, &encrypted); err != nil {
 		return
 	}
-	if encrypted.Version != DEFAULT_VERSION {
-		return nil, nil, errors.New("Unknown version")
+	if encrypted.Version != DEFAULT_VERSION && encrypted.Version != -1 {
+		return nil, nil, secure, errors.New("Unknown version")
 	}
 
+	secure = encrypted.Version == -1
+
+	hmacKey, err := c.records.GetHmacKey()
+	if err != nil {
+		return
+	}
+
+	if err = encrypted.unlock(hmacKey); err != nil {
+		return
+	}
+
+
 	// make sure file was encrypted with the active vault
 	vaultId, err := c.records.GetVaultId()
 	if err != nil {
 		return
 	}
 	if encrypted.VaultId != vaultId {
-		return nil, nil, errors.New("Wrong vault")
+		return nil, nil, secure, errors.New("Wrong vault")
 	}
 
 	// compute HMAC
-	hmacKey, err := c.records.GetHmacKey()
-	if err != nil {
-		return
-	}
 	expectedMAC := encrypted.computeHmac(hmacKey)
 	if !hmac.Equal(encrypted.Signature, expectedMAC) {
 		err = errors.New("Signature mismatch")
diff --git a/index.html b/index.html
index 1776365..20a7889 100644
--- a/index.html
+++ b/index.html
@@ -485,7 +485,7 @@
 					data : data,
 					success : function(d){
 					d = JSON.parse(window.atob(d.Response));
-					$form.find('.feedback').empty().append( makeAlert({ type: 'success', message: '<p>Successfully decrypted data:</p><pre>'+ window.atob(d.Data)+'</pre><p>Delegates: '+d.Delegates.sort().join(', ')+'</p>' }) );
+					$form.find('.feedback').empty().append( makeAlert({ type: (d.Secure ? 'success' : 'warning'), message: '<p>Successfully decrypted data:</p><pre>'+ window.atob(d.Data)+'</pre><p>Delegates: '+d.Delegates.sort().join(', ')+'</p>' }) );
 					}
 				});
 			});
diff --git a/redoctober.go b/redoctober.go
index 924f8bd..e7e909b 100644
--- a/redoctober.go
+++ b/redoctober.go
@@ -732,7 +732,7 @@ var indexHtml = []byte(`<!DOCTYPE html>
 					data : data,
 					success : function(d){
 					d = JSON.parse(window.atob(d.Response));
-					$form.find('.feedback').empty().append( makeAlert({ type: 'success', message: '<p>Successfully decrypted data:</p><pre>'+ window.atob(d.Data)+'</pre><p>Delegates: '+d.Delegates.sort().join(', ')+'</p>' }) );
+					$form.find('.feedback').empty().append( makeAlert({ type: (d.Secure ? 'success' : 'warning'), message: '<p>Successfully decrypted data:</p><pre>'+ window.atob(d.Data)+'</pre><p>Delegates: '+d.Delegates.sort().join(', ')+'</p>' }) );
 					}
 				});
 			});