diff --git a/README.ja.md b/README.ja.md
index e2d07885..dedc1db1 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -648,8 +648,8 @@ host         = "172.31.4.82"
     - containers: see [Usage: Scan Docker containers](https://github.com/future-architect/vuls/blob/master/README.ja.md#usage-scan-docker-containers)
 
 
-    Vulsは各サーバにSSHで接続するが、Goのネイティブ実装と、OSコマンドの２種類のSSH接続方法をサポートしている。
-    詳細は [-ssh-external option](https://github.com/future-architect/vuls/blob/master/README.ja.md#-ssh-external-option) を参照。
+    Vulsは各サーバにSSHで接続するが、OSコマンドでの接続と、Goのネイティブ実装の２種類のSSH接続方法をサポートしている。
+    詳細は [-ssh-native-insecure option](https://github.com/future-architect/vuls/blob/master/README.ja.md#-ssh-native-insecure-option) を参照。
 
     また、以下のSSH認証をサポートしている。
     - SSH agent
@@ -667,7 +667,7 @@ configtest:
                         [-config=/path/to/config.toml]
                         [-log-dir=/path/to/log]
                         [-ask-key-password]
-                        [-ssh-external]
+                        [-ssh-native-insecure]
                         [-containers-only]
                         [-timeout=300]
                         [-http-proxy=http://192.168.0.1:8080]
@@ -686,8 +686,8 @@ configtest:
         http://proxy-url:port (default: empty)
   -log-dir string
         /path/to/log (default "/var/log/vuls")
-  -ssh-external
-        Use external ssh command. Default: Use the Go native implementation
+  -ssh-native-insecure
+        Use Native Go implementation of SSH. Default: Use the external command
   -timeout int
         Timeout(Sec) (default 300)
 ```
@@ -761,7 +761,7 @@ scan:
                 [-results-dir=/path/to/results]
                 [-log-dir=/path/to/log]
                 [-cachedb-path=/path/to/cache.db]
-                [-ssh-external]
+                [-ssh-native-insecure]
                 [-containers-only]
                 [-skip-broken]
                 [-http-proxy=http://192.168.0.1:8080]
@@ -790,24 +790,24 @@ scan:
         /path/to/results
   -skip-broken
         [For CentOS] yum update changelog with --skip-broken option
-  -ssh-external
-        Use external ssh command. Default: Use the Go native implementation
+  -ssh-native-insecure
+        Use Native Go implementation of SSH. Default: Use the external command
 ```
 
-## -ssh-external option
+## -ssh-native-insecure option
 
 Vulsは２種類のSSH接続方法をサポートしている。
 
-デフォルトでは、Goのネイティブ実装 (crypto/ssh) を使ってスキャンする。
-これは、SSHコマンドがインストールされていない環境でも動作する（Windowsなど）  
 
-外部SSHコマンドを使ってスキャンするためには、`-ssh-external`を指定する。
+デフォルトでは、外部SSHコマンドを使ってスキャンする。
 SSH Configが使えるので、ProxyCommandを使った多段SSHなどが可能。  
 CentOSでは、スキャン対象サーバの/etc/sudoersに以下を追加する必要がある(user: vuls)
 ```
 Defaults:vuls !requiretty
 ```
 
+-ssh-native-insecureを指定すると、Goのネイティブ実装 (crypto/ssh) を使ってスキャンする。これは、SSHコマンドがインストールされていない環境でも動作する（Windowsなど）。-ssh-native-insecureは、ホストキーのチェックをしないことに注意すべき。
+
 ## -ask-key-password option
 
 | SSH key password |  -ask-key-password | |
diff --git a/README.md b/README.md
index 430cc6c5..2e5b6646 100644
--- a/README.md
+++ b/README.md
@@ -657,7 +657,7 @@ You can customize your configuration using this template.
     - optional: Add additional information to JSON report.
     - containers: see [Example: Scan containers (Docker/LXD)(#example-scan-containers-dockerlxd)
 
-    Vuls supports two types of SSH. One is native go implementation. The other is external SSH command. For details, see [-ssh-external option](https://github.com/future-architect/vuls#-ssh-external-option)
+    Vuls supports two types of SSH. One is external command. The other is native go implementation. For details, see [-ssh-native-insecure option](https://github.com/future-architect/vuls#-ssh-native-insecure-option)
 
     Multiple SSH authentication methods are supported.  
     - SSH agent
@@ -675,7 +675,7 @@ configtest:
                         [-config=/path/to/config.toml]
                         [-log-dir=/path/to/log]
                         [-ask-key-password]
-                        [-ssh-external]
+                        [-ssh-native-insecure]
                         [-containers-only]
                         [-timeout=300]
                         [-debug]
@@ -693,8 +693,8 @@ configtest:
         http://proxy-url:port (default: empty)
   -log-dir string
         /path/to/log (default "/var/log/vuls")
-  -ssh-external
-        Use external ssh command. Default: Use the Go native implementation
+  -ssh-native-insecure
+        Use Native Go implementation of SSH. Default: Use the external command
   -timeout int
         Timeout(Sec) (default 300)
 
@@ -772,7 +772,7 @@ scan:
                 [-results-dir=/path/to/results]
                 [-log-dir=/path/to/log]
                 [-cachedb-path=/path/to/cache.db]
-                [-ssh-external]
+                [-ssh-native-insecure]
                 [-containers-only]
                 [-skip-broken]
                 [-http-proxy=http://192.168.0.1:8080]
@@ -801,24 +801,26 @@ scan:
         /path/to/results
   -skip-broken
         [For CentOS] yum update changelog with --skip-broken option
-  -ssh-external
-        Use external ssh command. Default: Use the Go native implementation
+  -ssh-native-insecure
+        Use Native Go implementation of SSH. Default: Use the external command
 ```
 
-## -ssh-external option
+## -ssh-native-insecure option
 
 Vuls supports different types of SSH.  
 
-By Default, using a native Go implementation from crypto/ssh.   
-This is useful in situations where you may not have access to traditional UNIX tools.
-
-To use external SSH command, specify this option.   
+By Default, external SSH command will be used.
 This is useful If you want to use ProxyCommand or cipher algorithm of SSH that is not supported by native go implementation.  
 Don't forget to add below line to /etc/sudoers on the target servers. (username: vuls)
 ```
 Defaults:vuls !requiretty
 ```
 
+To use native Go implementation from crypto/ssh, specify this option.   
+This is useful in situations where you may not have access to traditional UNIX tools.
+But it is important to note that this mode does not check the host key.
+
+
 
 ## -ask-key-password option
 
diff --git a/commands/configtest.go b/commands/configtest.go
index a1f79214..dac1ab0f 100644
--- a/commands/configtest.go
+++ b/commands/configtest.go
@@ -36,7 +36,7 @@ type ConfigtestCmd struct {
 	logDir         string
 	askKeyPassword bool
 	containersOnly bool
-	sshExternal    bool
+	sshNative      bool
 	httpProxy      string
 	timeoutSec     int
 
@@ -94,10 +94,10 @@ func (p *ConfigtestCmd) SetFlags(f *flag.FlagSet) {
 	)
 
 	f.BoolVar(
-		&p.sshExternal,
-		"ssh-external",
+		&p.sshNative,
+		"ssh-native-insecure",
 		false,
-		"Use external ssh command. Default: Use the Go native implementation")
+		"Use Native Go implementation of SSH. Default: Use the external command")
 
 	f.BoolVar(
 		&p.containersOnly,
@@ -130,7 +130,7 @@ func (p *ConfigtestCmd) Execute(_ context.Context, f *flag.FlagSet, _ ...interfa
 		util.Log.Errorf("Please check README: https://github.com/future-architect/vuls#configuration")
 		return subcommands.ExitUsageError
 	}
-	c.Conf.SSHExternal = p.sshExternal
+	c.Conf.SSHNative = p.sshNative
 	c.Conf.HTTPProxy = p.httpProxy
 	c.Conf.ContainersOnly = p.containersOnly
 
diff --git a/commands/scan.go b/commands/scan.go
index f04005c2..7f4384bc 100644
--- a/commands/scan.go
+++ b/commands/scan.go
@@ -44,7 +44,7 @@ type ScanCmd struct {
 	askKeyPassword bool
 	containersOnly bool
 	skipBroken     bool
-	sshExternal    bool
+	sshNative      bool
 	pipe           bool
 }
 
@@ -62,7 +62,7 @@ func (*ScanCmd) Usage() string {
 		[-results-dir=/path/to/results]
 		[-log-dir=/path/to/log]
 		[-cachedb-path=/path/to/cache.db]
-		[-ssh-external]
+		[-ssh-native-insecure]
 		[-containers-only]
 		[-skip-broken]
 		[-http-proxy=http://192.168.0.1:8080]
@@ -97,10 +97,10 @@ func (p *ScanCmd) SetFlags(f *flag.FlagSet) {
 		"/path/to/cache.db (local cache of changelog for Ubuntu/Debian)")
 
 	f.BoolVar(
-		&p.sshExternal,
-		"ssh-external",
+		&p.sshNative,
+		"ssh-native-insecure",
 		false,
-		"Use external ssh command. Default: Use the Go native implementation")
+		"Use Native Go implementation of SSH. Default: Use the external command")
 
 	f.BoolVar(
 		&p.containersOnly,
@@ -202,7 +202,7 @@ func (p *ScanCmd) Execute(_ context.Context, f *flag.FlagSet, _ ...interface{})
 
 	c.Conf.ResultsDir = p.resultsDir
 	c.Conf.CacheDBPath = p.cacheDBPath
-	c.Conf.SSHExternal = p.sshExternal
+	c.Conf.SSHNative = p.sshNative
 	c.Conf.HTTPProxy = p.httpProxy
 	c.Conf.ContainersOnly = p.containersOnly
 	c.Conf.SkipBroken = p.skipBroken
diff --git a/config/config.go b/config/config.go
index ce1d73e0..3f6f9099 100644
--- a/config/config.go
+++ b/config/config.go
@@ -44,7 +44,7 @@ type Config struct {
 	CvssScoreOver      float64
 	IgnoreUnscoredCves bool
 
-	SSHExternal    bool
+	SSHNative      bool
 	ContainersOnly bool
 	SkipBroken     bool
 
@@ -82,8 +82,8 @@ type Config struct {
 func (c Config) ValidateOnConfigtest() bool {
 	errs := []error{}
 
-	if runtime.GOOS == "windows" && c.SSHExternal {
-		errs = append(errs, fmt.Errorf("-ssh-external cannot be used on windows"))
+	if runtime.GOOS == "windows" && !c.SSHNative {
+		errs = append(errs, fmt.Errorf("-ssh-native-insecure is needed on windows"))
 	}
 
 	_, err := valid.ValidateStruct(c)
@@ -114,8 +114,8 @@ func (c Config) ValidateOnScan() bool {
 		}
 	}
 
-	if runtime.GOOS == "windows" && c.SSHExternal {
-		errs = append(errs, fmt.Errorf("-ssh-external cannot be used on windows"))
+	if runtime.GOOS == "windows" && !c.SSHNative {
+		errs = append(errs, fmt.Errorf("-ssh-native-insecure is needed on windows"))
 	}
 
 	if len(c.ResultsDir) != 0 {
diff --git a/scan/executil.go b/scan/executil.go
index 232617d4..f780c0ac 100644
--- a/scan/executil.go
+++ b/scan/executil.go
@@ -151,10 +151,10 @@ func exec(c conf.ServerInfo, cmd string, sudo bool, log ...*logrus.Entry) (resul
 	if c.Port == "local" &&
 		(c.Host == "127.0.0.1" || c.Host == "localhost") {
 		result = localExec(c, cmd, sudo)
-	} else if conf.Conf.SSHExternal {
-		result = sshExecExternal(c, cmd, sudo)
-	} else {
+	} else if conf.Conf.SSHNative {
 		result = sshExecNative(c, cmd, sudo)
+	} else {
+		result = sshExecExternal(c, cmd, sudo)
 	}
 
 	logger := getSSHLogger(log...)