diff --git a/src/main/scala/app/AccountController.scala b/src/main/scala/app/AccountController.scala
index d19af7e..d0a0a89 100644
--- a/src/main/scala/app/AccountController.scala
+++ b/src/main/scala/app/AccountController.scala
@@ -5,6 +5,7 @@
 import util.StringUtil._
 import util.Directory._
 import util.ControlUtil._
+import ssh.SshUtil
 import jp.sf.amateras.scalatra.forms._
 import org.apache.commons.io.FileUtils
 import org.scalatra.i18n.Messages
@@ -49,7 +50,7 @@
 
   val sshKeyForm = mapping(
     "title"     -> trim(label("Title", text(required, maxlength(100)))),
-    "publicKey" -> trim(label("Key"  , text(required)))
+    "publicKey" -> trim(label("Key"  , text(required, validPublicKey)))
   )(SshKeyForm.apply)
 
   case class NewGroupForm(groupName: String, url: Option[String], fileId: Option[String], members: String)
@@ -435,4 +436,11 @@
       }) None else Some("Must select one manager at least.")
     }
   }
+
+  private def validPublicKey: Constraint = new Constraint(){
+    override def validate(name: String, value: String, messages: Messages): Option[String] = SshUtil.str2PublicKey(value) match {
+     case Some(_) => None
+     case None => Some("Key is invalid.")
+    }
+  }
 }