diff --git a/buffet/buffet_client.cc b/buffet/buffet_client.cc
index a874ec0..ef4bf03 100644
--- a/buffet/buffet_client.cc
+++ b/buffet/buffet_client.cc
@@ -313,17 +313,18 @@
 
   void CallRegisterDevice(const std::string& args,
                           ManagerProxy* manager_proxy) {
-    chromeos::VariantDictionary params;
+    std::string ticket_id;
     if (!args.empty()) {
       auto key_values = chromeos::data_encoding::WebParamsDecode(args);
       for (const auto& pair : key_values) {
-        params.insert(std::make_pair(pair.first, chromeos::Any(pair.second)));
+        if (pair.first == "ticket_id")
+          ticket_id = pair.second;
       }
     }
 
     ErrorPtr error;
     std::string device_id;
-    if (!manager_proxy->RegisterDevice(params, &device_id, &error)) {
+    if (!manager_proxy->RegisterDevice(ticket_id, &device_id, &error)) {
       return ReportError(error.get());
     }
 
@@ -380,8 +381,8 @@
   }
 
   void CallSetCommandVisibility(const std::string& command_list,
-                                    const std::string& visibility,
-                                    ManagerProxy* manager_proxy) {
+                                const std::string& visibility,
+                                ManagerProxy* manager_proxy) {
     ErrorPtr error;
     std::vector<std::string> commands =
         chromeos::string_utils::Split(command_list, ",", true, true);
diff --git a/buffet/dbus_bindings/org.chromium.Buffet.Manager.xml b/buffet/dbus_bindings/org.chromium.Buffet.Manager.xml
index 67c265d..73d3547 100644
--- a/buffet/dbus_bindings/org.chromium.Buffet.Manager.xml
+++ b/buffet/dbus_bindings/org.chromium.Buffet.Manager.xml
@@ -17,7 +17,7 @@
       <annotation name="org.chromium.DBus.Method.Kind" value="async"/>
     </method>
     <method name="RegisterDevice">
-      <arg name="params" type="a{sv}" direction="in"/>
+      <arg name="ticket_id" type="s" direction="in"/>
       <arg name="device_id" type="s" direction="out"/>
       <annotation name="org.chromium.DBus.Method.Kind" value="async"/>
     </method>
diff --git a/buffet/device_registration_info.cc b/buffet/device_registration_info.cc
index 7d8c608..454853b 100644
--- a/buffet/device_registration_info.cc
+++ b/buffet/device_registration_info.cc
@@ -26,7 +26,6 @@
 #include "buffet/commands/command_definition.h"
 #include "buffet/commands/command_manager.h"
 #include "buffet/commands/schema_constants.h"
-#include "buffet/device_registration_storage_keys.h"
 #include "buffet/notification/xmpp_channel.h"
 #include "buffet/states/state_manager.h"
 #include "buffet/utils.h"
@@ -35,23 +34,6 @@
 const char buffet::kErrorDomainGCD[] = "gcd";
 const char buffet::kErrorDomainGCDServer[] = "gcd_server";
 
-namespace buffet {
-namespace storage_keys {
-
-// Persistent keys
-const char kRefreshToken[] = "refresh_token";
-const char kDeviceId[] = "device_id";
-const char kRobotAccount[] = "robot_account";
-const char kName[] = "name";
-const char kDescription[] = "description";
-const char kLocation[] = "location";
-const char kLocalAnonymousAccessRole[] = "local_anonymous_access_role";
-const char kLocalDiscoveryEnabled[] = "local_discovery_enabled";
-const char kLocalPairingEnabled[] = "local_pairing_enabled";
-
-}  // namespace storage_keys
-}  // namespace buffet
-
 namespace {
 
 const int kMaxStartDeviceRetryDelayMinutes{1};
@@ -390,47 +372,8 @@
   return json;
 }
 
-namespace {
-
-bool GetWithDefault(const std::map<std::string, std::string>& source,
-                    const std::string& key,
-                    const std::string& default_value,
-                    std::string* output) {
-  auto it = source.find(key);
-  if (it == source.end()) {
-    *output = default_value;
-    return false;
-  }
-  *output = it->second;
-  return true;
-}
-
-}  // namespace
-
-std::string DeviceRegistrationInfo::RegisterDevice(
-    const std::map<std::string, std::string>& params,
-    chromeos::ErrorPtr* error) {
-  std::string ticket_id;
-  if (!GetWithDefault(params, "ticket_id", "", &ticket_id)) {
-    chromeos::Error::AddTo(error, FROM_HERE, kErrorDomainBuffet,
-                           "missing_parameter",
-                           "Need ticket_id parameter for RegisterDevice()");
-    return std::string();
-  }
-
-  // These fields are optional, and will default to values from the manufacturer
-  // supplied config.
-  std::string name;
-  GetWithDefault(params, storage_keys::kName, config_->name(), &name);
-  std::string description;
-  GetWithDefault(params, storage_keys::kDescription, config_->description(),
-                 &description);
-  std::string location;
-  GetWithDefault(params, storage_keys::kLocation, config_->location(),
-                 &location);
-  if (!UpdateDeviceInfo(name, description, location, error))
-    return std::string();
-
+std::string DeviceRegistrationInfo::RegisterDevice(const std::string& ticket_id,
+                                                   chromeos::ErrorPtr* error) {
   std::unique_ptr<base::DictionaryValue> device_draft =
       BuildDeviceResource(error);
   if (!device_draft)
diff --git a/buffet/device_registration_info.h b/buffet/device_registration_info.h
index c9ca7b4..5a9a1a3 100644
--- a/buffet/device_registration_info.h
+++ b/buffet/device_registration_info.h
@@ -105,13 +105,8 @@
       chromeos::ErrorPtr* error);
 
   // Registers the device.
-  //
-  // |params| are a list of key-value pairs of device information,
-  // such as client_id, client_secret, and so on. If a particular key-value pair
-  // is omitted, a default value is used when possible.
   // Returns a device ID on success.
-  // The values are all strings for now.
-  std::string RegisterDevice(const std::map<std::string, std::string>& params,
+  std::string RegisterDevice(const std::string& ticket_id,
                              chromeos::ErrorPtr* error);
 
   // Updates a command.
diff --git a/buffet/device_registration_info_unittest.cc b/buffet/device_registration_info_unittest.cc
index f41d408..e3e9d22 100644
--- a/buffet/device_registration_info_unittest.cc
+++ b/buffet/device_registration_info_unittest.cc
@@ -16,7 +16,6 @@
 
 #include "buffet/commands/command_manager.h"
 #include "buffet/commands/unittest_utils.h"
-#include "buffet/device_registration_storage_keys.h"
 #include "buffet/states/mock_state_change_queue_interface.h"
 #include "buffet/states/state_manager.h"
 #include "buffet/storage_impls.h"
@@ -55,14 +54,13 @@
                                      "VZDei530-w0yE2urpQ";
 const char kUserRefreshToken[]     = "1/zQLKjlKJlkLkLKjLkjLKjLkjLjLkjl0ftc6"
                                      "cp1nI-GQ";
-
 }  // namespace test_data
 
 // Add the test device registration information.
 void SetDefaultDeviceRegistration(base::DictionaryValue* data) {
-  data->SetString(storage_keys::kRefreshToken, test_data::kRefreshToken);
-  data->SetString(storage_keys::kDeviceId, test_data::kDeviceId);
-  data->SetString(storage_keys::kRobotAccount, test_data::kRobotAccountEmail);
+  data->SetString("refresh_token", test_data::kRefreshToken);
+  data->SetString("device_id", test_data::kDeviceId);
+  data->SetString("robot_account", test_data::kRobotAccountEmail);
 }
 
 void OAuth2Handler(const ServerRequest& request, ServerResponse* response) {
@@ -447,9 +445,8 @@
   transport_->AddHandler(dev_reg_->GetOAuthURL("token"),
                          chromeos::http::request_type::kPost,
                          base::Bind(OAuth2Handler));
-  std::map<std::string, std::string> params;
-  params["ticket_id"] = test_data::kClaimTicketId;
-  std::string device_id = dev_reg_->RegisterDevice(params, nullptr);
+  std::string device_id =
+      dev_reg_->RegisterDevice(test_data::kClaimTicketId, nullptr);
 
   EXPECT_EQ(test_data::kDeviceId, device_id);
   EXPECT_EQ(3, transport_->GetRequestCount());
@@ -460,11 +457,11 @@
   base::DictionaryValue* dict = nullptr;
   EXPECT_TRUE(storage_data->GetAsDictionary(&dict));
   std::string value;
-  EXPECT_TRUE(dict->GetString(storage_keys::kDeviceId, &value));
+  EXPECT_TRUE(dict->GetString("device_id", &value));
   EXPECT_EQ(test_data::kDeviceId, value);
-  EXPECT_TRUE(dict->GetString(storage_keys::kRefreshToken, &value));
+  EXPECT_TRUE(dict->GetString("refresh_token", &value));
   EXPECT_EQ(test_data::kRefreshToken, value);
-  EXPECT_TRUE(dict->GetString(storage_keys::kRobotAccount, &value));
+  EXPECT_TRUE(dict->GetString("robot_account", &value));
   EXPECT_EQ(test_data::kRobotAccountEmail, value);
 }
 
diff --git a/buffet/device_registration_storage_keys.h b/buffet/device_registration_storage_keys.h
deleted file mode 100644
index 5ce8083..0000000
--- a/buffet/device_registration_storage_keys.h
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright 2014 The Chromium OS Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BUFFET_DEVICE_REGISTRATION_STORAGE_KEYS_H_
-#define BUFFET_DEVICE_REGISTRATION_STORAGE_KEYS_H_
-
-// These are the keys used to identify specific device registration information
-// being saved to a storage. Used mostly internally by DeviceRegistrationInfo
-// but also exposed so that tests can access them.
-namespace buffet {
-namespace storage_keys {
-
-extern const char kRefreshToken[];
-extern const char kDeviceId[];
-extern const char kRobotAccount[];
-extern const char kName[];
-extern const char kDescription[];
-extern const char kLocation[];
-extern const char kLocalAnonymousAccessRole[];
-extern const char kLocalDiscoveryEnabled[];
-extern const char kLocalPairingEnabled[];
-
-}  // namespace storage_keys
-}  // namespace buffet
-
-#endif  // BUFFET_DEVICE_REGISTRATION_STORAGE_KEYS_H_
diff --git a/buffet/manager.cc b/buffet/manager.cc
index d21ec8b..78a0a8c 100644
--- a/buffet/manager.cc
+++ b/buffet/manager.cc
@@ -116,22 +116,11 @@
 }
 
 void Manager::RegisterDevice(DBusMethodResponse<std::string> response,
-                             const chromeos::VariantDictionary& params) {
+                             const std::string& ticket_id) {
   LOG(INFO) << "Received call to Manager.RegisterDevice()";
 
   chromeos::ErrorPtr error;
-  std::map<std::string, std::string> str_params;
-  for (const auto& pair : params) {
-    if (!pair.second.IsTypeCompatible<std::string>()) {
-      response->ReplyWithError(FROM_HERE, chromeos::errors::dbus::kDomain,
-                               DBUS_ERROR_INVALID_ARGS,
-                               "String value expected");
-      return;
-    }
-    str_params.emplace_hint(str_params.end(), pair.first,
-                            pair.second.Get<std::string>());
-  }
-  std::string device_id = device_info_->RegisterDevice(str_params, &error);
+  std::string device_id = device_info_->RegisterDevice(ticket_id, &error);
   if (!device_id.empty()) {
     response->Return(device_id);
     return;
diff --git a/buffet/manager.h b/buffet/manager.h
index 479ac9b..b15d7b0 100644
--- a/buffet/manager.h
+++ b/buffet/manager.h
@@ -62,7 +62,7 @@
   void CheckDeviceRegistered(DBusMethodResponse<std::string> response) override;
   void GetDeviceInfo(DBusMethodResponse<std::string> response) override;
   void RegisterDevice(DBusMethodResponse<std::string> response,
-                      const chromeos::VariantDictionary& params) override;
+                      const std::string& ticket_id) override;
   bool UpdateDeviceInfo(chromeos::ErrorPtr* error,
                         const std::string& in_name,
                         const std::string& in_description,