diff --git a/session/common.go b/session/common.go
index 9a83327..72864fb 100644
--- a/session/common.go
+++ b/session/common.go
@@ -19,7 +19,7 @@ type Authorization struct {
 	// by authorization provider
 	Platform string `bson:"p" json:"p"`
 	Uid      string `bson:"u" json:"u"`
-	Email    string `bson:"em" json:"em"`
+	Alias    string `bson:"al" json:"al"`
 }
 
 func (auth *Authorization) ToStrings() []string {
@@ -27,7 +27,7 @@ func (auth *Authorization) ToStrings() []string {
 		"a", auth.Account.Hex(),
 		"p", auth.Platform,
 		"u", auth.Uid,
-		"em", auth.Email,
+		"al", auth.Alias,
 		"inv", auth.invalidated,
 	}
 }
@@ -42,7 +42,7 @@ func MakeAuthrizationFromStringMap(src map[string]string) Authorization {
 		Account:     accid,
 		Platform:    src["p"],
 		Uid:         src["u"],
-		Email:       src["em"],
+		Alias:       src["al"],
 		invalidated: src["inv"],
 	}
 }