diff --git a/controller/auth.go b/controller/auth.go
index e86d823..3f5472b 100644
--- a/controller/auth.go
+++ b/controller/auth.go
@@ -13,6 +13,7 @@ import (
 	"github.com/kataras/jwt"
 	"go.uber.org/zap"
 	"golang.org/x/crypto/bcrypt"
+	"strings"
 	"time"
 )
 
@@ -201,6 +202,8 @@ func (a *AuthController) PostPubkeyChallenge() {
 		return
 	}
 
+	r.Pubkey = strings.ToLower(r.Pubkey)
+
 	// Retrieve the account for the given email.
 	account := model.Key{}
 	if err := db.Get().Where("pubkey = ?", r.Pubkey).First(&account).Error; err != nil {