diff --git a/config/v3-to-v4.php b/config/v3-to-v4.php
index 8b88c1f..36d55f9 100644
--- a/config/v3-to-v4.php
+++ b/config/v3-to-v4.php
@@ -1,12 +1,16 @@
 <?php
 use Rector\Config\RectorConfig;
 
-use phpseclib\rectorRules\Rector\V3toV4\X509NodeVisitor;
+use phpseclib\rectorRules\Rector\V3toV4\CryptRandom;
+use phpseclib\rectorRules\Rector\V3toV4\Namespace_;
+use phpseclib\rectorRules\Rector\V3toV4\SFTPChmod;
 use phpseclib\rectorRules\Rector\V3toV4\X509;
 
 return RectorConfig::configure()
-  ->registerDecoratingNodeVisitor(X509NodeVisitor::class)
   ->withRules([
+    Namespace_::class,
+    CryptRandom::class,
+    SFTPChmod::class,
     X509::class,
   ])
   ->withPreparedSets(
diff --git a/src/Rector/V3toV4/CryptRandom.php b/src/Rector/V3toV4/CryptRandom.php
new file mode 100644
index 0000000..d1d9fec
--- /dev/null
+++ b/src/Rector/V3toV4/CryptRandom.php
@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace phpseclib\rectorRules\Rector\V3toV4;
+
+use PhpParser\Node;
+use PhpParser\Node\Name;
+use PhpParser\Node\UseItem;
+use PhpParser\Node\Stmt\Use_;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Expr\StaticCall;
+use PhpParser\NodeTraverser;
+use Rector\Rector\AbstractRector;
+
+/**
+ * Replaces phpseclib3\Crypt\Random::string($n) with random_bytes($n).
+ *
+ * phpseclib3\Crypt\Random existed because PHP 5.6 had no built-in CSPRNG.
+ * PHP 7+ ships random_bytes(), which phpseclib 4 uses directly — the class
+ * was removed entirely. Both the use-import and every call site are rewritten.
+ *
+ * Before:
+ *   use phpseclib3\Crypt\Random;
+ *   $bytes = Random::string(32);
+ *
+ * After:
+ *   $bytes = random_bytes(32);
+ */
+final class CryptRandom extends AbstractRector
+{
+  public function getNodeTypes(): array
+  {
+    return [Use_::class, StaticCall::class];
+  }
+
+  public function refactor(Node $node): int|null|Node
+  {
+    if ($node instanceof Use_) {
+      $node->uses = array_values(array_filter(
+        $node->uses,
+        fn(UseItem $item) => !$this->isName($item->name, 'phpseclib3\Crypt\Random')
+      ));
+
+      // Remove the Use_ statement entirely if it now has no items
+      return count($node->uses) > 0 ? $node : NodeTraverser::REMOVE_NODE;
+    }
+
+    if (!$node instanceof StaticCall) {
+      return null;
+    }
+
+    if (!$this->isNames($node->class, ['Random', 'phpseclib3\Crypt\Random'])) {
+      return null;
+    }
+
+    if (!$this->isName($node->name, 'string')) {
+      return null;
+    }
+
+    return new FuncCall(new Name('random_bytes'), $node->args);
+  }
+}
diff --git a/src/Rector/V3toV4/Namespace_.php b/src/Rector/V3toV4/Namespace_.php
new file mode 100644
index 0000000..b7e2045
--- /dev/null
+++ b/src/Rector/V3toV4/Namespace_.php
@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+namespace phpseclib\rectorRules\Rector\V3toV4;
+
+use PhpParser\Node;
+use PhpParser\Node\Name;
+use PhpParser\Node\Name\FullyQualified;
+use PhpParser\Node\UseItem;
+use Rector\Rector\AbstractRector;
+
+/**
+ * Renames the phpseclib3\ root namespace to phpseclib4\ everywhere — in use
+ * statements and in fully-qualified names used inline.
+ *
+ * Short names (e.g. RSA in "use phpseclib3\Crypt\RSA; new RSA()") are left
+ * alone: renaming the use statement is sufficient for them to resolve correctly.
+ *
+ * Classes deliberately skipped here (handled by dedicated rules):
+ *   - phpseclib3\File\X509  → split into X509 / CSR / CRL / SPKAC (X509 rule)
+ *   - phpseclib3\Crypt\Random → removed; replaced by random_bytes() (CryptRandom rule)
+ */
+final class Namespace_ extends AbstractRector
+{
+  private const SKIP = [
+    'phpseclib3\File\X509',
+    'phpseclib3\Crypt\Random',
+  ];
+
+  public function getNodeTypes(): array
+  {
+    return [UseItem::class, FullyQualified::class];
+  }
+
+  public function refactor(Node $node): ?Node
+  {
+    if ($node instanceof UseItem) {
+      $name = $node->name->toString();
+      if (!str_starts_with($name, 'phpseclib3\\')) {
+        return null;
+      }
+      if (in_array($name, self::SKIP, true)) {
+        return null;
+      }
+      $node->name = new Name('phpseclib4\\' . substr($name, strlen('phpseclib3\\')));
+      return $node;
+    }
+
+    // FullyQualified — only rename if written explicitly in source (not resolved from a short name).
+    // Resolved short names occupy file-character span of the alias only (e.g. 4 chars for "SFTP"),
+    // while explicit FQNs span the full string including the leading backslash.
+    $name = $node->toString();
+    if (!str_starts_with($name, 'phpseclib3\\')) {
+      return null;
+    }
+    if (in_array($name, self::SKIP, true)) {
+      return null;
+    }
+    $expectedSpan = strlen('\\' . $name);
+    $actualSpan = $node->getEndFilePos() - $node->getStartFilePos() + 1;
+    if ($actualSpan !== $expectedSpan) {
+      // Span doesn't match the full FQN — this was resolved from a short name via a use import.
+      return null;
+    }
+
+    return new FullyQualified('phpseclib4\\' . substr($name, strlen('phpseclib3\\')));
+  }
+}
diff --git a/src/Rector/V3toV4/README.md b/src/Rector/V3toV4/README.md
index cf702e9..8564969 100644
--- a/src/Rector/V3toV4/README.md
+++ b/src/Rector/V3toV4/README.md
@@ -29,8 +29,9 @@ The rule performs the following transformations:
 - Converts instance method calls into the corresponding static calls on the appropriate phpseclib4 class.
 - Migrates calls such as:
     - `loadX509()` → `X509::load()`
-    - `loadCSR()` → `CSR::loadCSR()`
-    - `loadCRL()` → `CRL::loadCRL()`
+    - `loadCSR()` → `CSR::load()`
+    - `loadCRL()` → `CRL::load()`
+    - `loadSPKAC()` → `SPKAC::load()`
 - Rewrites API changes:
     - `getDN()` → `getSubjectDN(X509::DN_ARRAY)`
     - `setDNProp()` → `addDNProp()`
@@ -112,7 +113,7 @@ $csr = $x509->loadCSR(file_get_contents('csr.csr'));
 ```
 will be refactored to
 ```php
-$csr = \phpseclib4\File\CSR::loadCSR(file_get_contents('csr.csr'));
+$csr = \phpseclib4\File\CSR::load(file_get_contents('csr.csr'));
 ```
 
 #### Set DN Prop
@@ -159,7 +160,7 @@ $crl = $x509->loadCRL(file_get_contents('crl.bin'));
 ```
 will be refactored to
 ```php
-$crl = \phpseclib4\File\CRL::loadCRL(file_get_contents('crl.bin'));
+$crl = \phpseclib4\File\CRL::load(file_get_contents('crl.bin'));
 ```
 
 ### SPKAC
@@ -172,10 +173,10 @@ $spkac = $x509->loadSPKAC(file_get_contents('spkac.txt'));
 ```
 will be refactored to
 ```php
-$spkac = \phpseclib4\File\CRL::loadCRL(file_get_contents('spkac.txt'));
+$spkac = \phpseclib4\File\SPKAC::load(file_get_contents('spkac.txt'));
 ```
 
-#### Read cert
+#### Create SPKAC
 
 ```php
 $x509 = new X509();
@@ -185,7 +186,7 @@ $spkac = $x509->signSPKAC();
 ```
 will be refactored to
 ```php
-$spkac = \phpseclib4\File\CRL::loadCRL($privKey->getPublicKey());
+$spkac = new \phpseclib4\File\SPKAC($privKey->getPublicKey());
 $spkac->setChallenge('123456789');
 $privKey->sign($spkac);
 ```
diff --git a/src/Rector/V3toV4/SFTPChmod.php b/src/Rector/V3toV4/SFTPChmod.php
new file mode 100644
index 0000000..ae88293
--- /dev/null
+++ b/src/Rector/V3toV4/SFTPChmod.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace phpseclib\rectorRules\Rector\V3toV4;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Scalar\Int_;
+use Rector\Rector\AbstractRector;
+
+/**
+ * Swaps the argument order of SFTP::chmod() from v3's (mode, path) to v4's (path, mode).
+ *
+ * phpseclib 3: $sftp->chmod(0777, 'file.txt')
+ * phpseclib 4: $sftp->chmod('file.txt', 0777)
+ *
+ * Detection heuristic: any ->chmod() call whose first argument is an integer
+ * literal. PHP's built-in chmod() is a function (not a method), so there is
+ * no false-positive risk there; and no other common class exposes chmod(int, string).
+ */
+final class SFTPChmod extends AbstractRector
+{
+  public function getNodeTypes(): array
+  {
+    return [MethodCall::class];
+  }
+
+  public function refactor(Node $node): ?Node
+  {
+    if (!$node instanceof MethodCall) {
+      return null;
+    }
+
+    if (!$this->isName($node->name, 'chmod')) {
+      return null;
+    }
+
+    // Only act when the v3 signature is present: first arg is an int literal (octal mode)
+    if (!isset($node->args[0], $node->args[1])) {
+      return null;
+    }
+
+    if (!$node->args[0]->value instanceof Int_) {
+      return null;
+    }
+
+    // Swap path and mode — args[2] (recursive flag) stays in place
+    [$node->args[0], $node->args[1]] = [$node->args[1], $node->args[0]];
+
+    return $node;
+  }
+}
diff --git a/src/Rector/V3toV4/X509.php b/src/Rector/V3toV4/X509.php
index 61179d6..ed9dba9 100644
--- a/src/Rector/V3toV4/X509.php
+++ b/src/Rector/V3toV4/X509.php
@@ -4,6 +4,7 @@
 
 namespace phpseclib\rectorRules\Rector\V3toV4;
 
+use PhpParser\NodeFinder;
 use PhpParser\NodeTraverser;
 use PhpParser\Node;
 use PhpParser\Node\Arg;
@@ -38,12 +39,20 @@ final class X509 extends AbstractRector
 
   // targetClass, targetMethod
   private const METHOD_TO_CLASS = [
-    'loadX509' => ['phpseclib4\File\X509', 'load'],
-    'loadCSR'  => ['phpseclib4\File\CSR', 'loadCSR'],
-    'loadCRL'  => ['phpseclib4\File\CRL', 'loadCRL'],
-    'loadSPKAC'=> ['phpseclib4\File\CRL', 'loadCRL'],
-    'setPrivateKey'=> ['phpseclib4\File\CRL', 'loadCRL'], // Set to CRL per default
-    // 'setPrivateKey'=> ['phpseclib4\File\CSR', 'new CSR($privKey->getPublicKey())'],
+    'loadX509'     => ['phpseclib4\File\X509',  'load'],
+    'loadCSR'      => ['phpseclib4\File\CSR',   'load'],
+    'loadCRL'      => ['phpseclib4\File\CRL',   'load'],
+    'loadSPKAC'    => ['phpseclib4\File\SPKAC', 'load'],
+    'setPrivateKey'=> ['phpseclib4\File\SPKAC', 'load'],
+  ];
+
+  // Methods that identify which phpseclib4 class to import (visitor analysis)
+  private const IMPORT_METHOD_MAP = [
+    'loadX509'  => 'phpseclib4\File\X509',
+    'getDN'     => 'phpseclib4\File\X509',
+    'loadCSR'   => 'phpseclib4\File\CSR',
+    'loadCRL'   => 'phpseclib4\File\CRL',
+    'loadSPKAC' => 'phpseclib4\File\SPKAC',
   ];
 
   public function getNodeTypes(): array
@@ -56,6 +65,112 @@ public function getNodeTypes(): array
     ];
   }
 
+  /**
+   * Performs the pre-analysis that X509NodeVisitor used to provide as a decorator.
+   * Sets attributes on Class_ nodes and populates $this->usedImports.
+   * Must run before any Class_/MethodCall refactoring takes place.
+   */
+  private function analyzeFile(FileNode $node): void
+  {
+    $this->usedImports = [];
+    $finder = new NodeFinder();
+
+    /** @var Class_[] $classes */
+    $classes = $finder->findInstanceOf($node->stmts, Class_::class);
+    foreach ($classes as $class) {
+      $hasCsrMethodCall  = false;
+      $hasX509MethodCall = false;
+      $hasSetPrivateKey  = false;
+      $hasSetPublicKey   = false;
+      $privKeyObj        = null;
+      $pubKeyObj         = null;
+      $issuerVar         = null;
+      $subjectVar        = null;
+
+      /** @var MethodCall[] $methodCalls */
+      $methodCalls = $finder->findInstanceOf($class->stmts, MethodCall::class);
+      foreach ($methodCalls as $methodCall) {
+        if (!$methodCall->name instanceof Identifier) {
+          continue;
+        }
+        $methodName = $methodCall->name->toString();
+        $varName    = ($methodCall->var instanceof Variable && is_string($methodCall->var->name))
+          ? $methodCall->var->name
+          : null;
+
+        if ($methodName === 'setPrivateKey') {
+          $hasSetPrivateKey = true;
+          $arg = $methodCall->args[0]->value ?? null;
+          if ($arg instanceof Variable && is_string($arg->name)) {
+            $privKeyObj = $arg->name;
+          }
+          $issuerVar = $varName;
+        }
+
+        if ($methodName === 'setPublicKey') {
+          $hasSetPublicKey = true;
+          $arg = $methodCall->args[0]->value ?? null;
+          if ($arg instanceof Variable && is_string($arg->name)) {
+            $pubKeyObj = $arg->name;
+          }
+          $subjectVar = $varName;
+        }
+
+        if (in_array($methodName, ['loadCSR', 'signCSR', 'saveCSR'], true)) {
+          $hasCsrMethodCall = true;
+        }
+        if (in_array($methodName, ['setPublicKey', 'saveX509', 'setDN'], true)) {
+          $hasX509MethodCall = true;
+        }
+
+        if (isset(self::IMPORT_METHOD_MAP[$methodName])) {
+          $this->usedImports[self::IMPORT_METHOD_MAP[$methodName]] = true;
+        }
+      }
+
+      if ($hasCsrMethodCall) {
+        $class->setAttribute(X509NodeVisitor::IS_CSR, true);
+      }
+
+      if ($hasX509MethodCall) {
+        $class->setAttribute(X509NodeVisitor::IS_X509, true);
+
+        $x509Assignments = $finder->find($class->stmts, function (Node $n): bool {
+          return $n instanceof Assign
+            && $n->expr instanceof New_
+            && $n->expr->class instanceof Name
+            && in_array($n->expr->class->toString(), ['X509', 'phpseclib3\File\X509'], true);
+        });
+
+        if (count($x509Assignments) === 3) {
+          $x509Assignments[0]->setAttribute(X509NodeVisitor::IS_FIRST_X509_ASSIGNMENT, true);
+        }
+      }
+
+      if ($subjectVar !== null) {
+        $class->setAttribute(X509NodeVisitor::SUBJECT_VAR, $subjectVar);
+      }
+      if ($issuerVar !== null) {
+        $class->setAttribute(X509NodeVisitor::ISSUER_VAR, $issuerVar);
+      }
+
+      if ($hasSetPrivateKey) {
+        $class->setAttribute(X509NodeVisitor::PRIV_KEY_OBJ, $privKeyObj);
+
+        if ($class->getAttribute(X509NodeVisitor::IS_CSR, false)) {
+          $this->usedImports['phpseclib4\File\CSR'] = true;
+        } elseif ($class->getAttribute(X509NodeVisitor::IS_X509, false)) {
+          $this->usedImports['phpseclib4\File\X509'] = true;
+        } else {
+          $this->usedImports['phpseclib4\File\SPKAC'] = true;
+        }
+      }
+      if ($hasSetPublicKey) {
+        $class->setAttribute(X509NodeVisitor::PUB_KEY_OBJ, $pubKeyObj);
+      }
+    }
+  }
+
   private function stmtsWithoutLegacyImport($stmts) {
     return array_values(array_filter($stmts, function ($stmt) {
       if (!$stmt instanceof Use_) {
@@ -101,7 +216,11 @@ private function reset() {
   public function refactor(Node $node): int|null|Node
   {
     if($node instanceof FileNode) {
-      $this->usedImports = $node->getAttribute('usedImports', []);
+      // Perform the pre-analysis (previously done by X509NodeVisitor) to avoid
+      // depending on the decorator mechanism, which has singleton-lifetime issues
+      // in combined PHPUnit runs.
+      $this->analyzeFile($node);
+
       // Remove old import
       $node->stmts = $this->stmtsWithoutLegacyImport($node->stmts);
 
@@ -260,7 +379,7 @@ public function refactor(Node $node): int|null|Node
 
         return new Assign(
           new Variable('spkac'),
-          new StaticCall(new Name($shortClass), $targetMethod, $args)
+          new New_(new Name($shortClass), $args)
         );
       }
 
diff --git a/src/Rector/V3toV4/X509NodeVisitor.php b/src/Rector/V3toV4/X509NodeVisitor.php
index 4c610a8..177d835 100644
--- a/src/Rector/V3toV4/X509NodeVisitor.php
+++ b/src/Rector/V3toV4/X509NodeVisitor.php
@@ -35,11 +35,11 @@ final class X509NodeVisitor extends NodeVisitorAbstract implements DecoratingNod
   public const ISSUER_VAR = 'issuer_var';
 
   private const METHOD_TO_CLASS = [
-    'loadX509' => 'phpseclib4\File\X509',
-    'getDN' => 'phpseclib4\File\X509',
-    'loadCSR'  => 'phpseclib4\File\CSR',
-    'loadCRL'  => 'phpseclib4\File\CRL',
-    'loadSPKAC'=> 'phpseclib4\File\CRL',
+    'loadX509'  => 'phpseclib4\File\X509',
+    'getDN'     => 'phpseclib4\File\X509',
+    'loadCSR'   => 'phpseclib4\File\CSR',
+    'loadCRL'   => 'phpseclib4\File\CRL',
+    'loadSPKAC' => 'phpseclib4\File\SPKAC',
   ];
 
   public function __construct(
@@ -150,7 +150,7 @@ public function enterNode(Node $node): ?Node
         } elseif ($class->getAttribute(self::IS_X509, false)) {
           $usedImports['phpseclib4\File\X509'] = true;
         } else {
-          $usedImports['phpseclib4\File\CRL'] = true;
+          $usedImports['phpseclib4\File\SPKAC'] = true;
         }
       }
       if ($hasSetPublicKey) {
diff --git a/tests/V3toV4/CryptRandom/CryptRandomTest.php b/tests/V3toV4/CryptRandom/CryptRandomTest.php
new file mode 100644
index 0000000..f99b8e2
--- /dev/null
+++ b/tests/V3toV4/CryptRandom/CryptRandomTest.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\V3toV4\CryptRandom;
+
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class CryptRandomTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): \Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/rule.php';
+    }
+}
diff --git a/tests/V3toV4/CryptRandom/Fixture/crypt_random_fqn.php.inc b/tests/V3toV4/CryptRandom/Fixture/crypt_random_fqn.php.inc
new file mode 100644
index 0000000..98fc81a
--- /dev/null
+++ b/tests/V3toV4/CryptRandom/Fixture/crypt_random_fqn.php.inc
@@ -0,0 +1,23 @@
+<?php
+
+class CryptRandomFQNClass
+{
+    public function foo(): string
+    {
+        return \phpseclib3\Crypt\Random::string(16);
+    }
+}
+
+?>
+-----
+<?php
+
+class CryptRandomFQNClass
+{
+    public function foo(): string
+    {
+        return random_bytes(16);
+    }
+}
+
+?>
diff --git a/tests/V3toV4/CryptRandom/Fixture/crypt_random_use.php.inc b/tests/V3toV4/CryptRandom/Fixture/crypt_random_use.php.inc
new file mode 100644
index 0000000..3bf5354
--- /dev/null
+++ b/tests/V3toV4/CryptRandom/Fixture/crypt_random_use.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+use phpseclib3\Crypt\Random;
+
+class CryptRandomClass
+{
+    public function foo(): string
+    {
+        return Random::string(32);
+    }
+}
+
+?>
+-----
+<?php
+
+class CryptRandomClass
+{
+    public function foo(): string
+    {
+        return random_bytes(32);
+    }
+}
+
+?>
diff --git a/tests/V3toV4/CryptRandom/config/rule.php b/tests/V3toV4/CryptRandom/config/rule.php
new file mode 100644
index 0000000..ab46a2f
--- /dev/null
+++ b/tests/V3toV4/CryptRandom/config/rule.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use phpseclib\rectorRules\Rector\V3toV4\CryptRandom;
+
+return RectorConfig::configure()
+  ->withRules([CryptRandom::class]);
diff --git a/tests/V3toV4/Namespace_/Fixture/namespace_fqn.php.inc b/tests/V3toV4/Namespace_/Fixture/namespace_fqn.php.inc
new file mode 100644
index 0000000..00723a0
--- /dev/null
+++ b/tests/V3toV4/Namespace_/Fixture/namespace_fqn.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+class NamespaceFQNClass
+{
+    public function foo(): void
+    {
+        $sftp = new \phpseclib3\Net\SFTP('example.com');
+        $n = new \phpseclib3\Math\BigInteger(42);
+        $key = \phpseclib3\Crypt\RSA::createKey();
+    }
+}
+
+?>
+-----
+<?php
+
+class NamespaceFQNClass
+{
+    public function foo(): void
+    {
+        $sftp = new \phpseclib4\Net\SFTP('example.com');
+        $n = new \phpseclib4\Math\BigInteger(42);
+        $key = \phpseclib4\Crypt\RSA::createKey();
+    }
+}
+
+?>
diff --git a/tests/V3toV4/Namespace_/Fixture/namespace_skip_x509.php.inc b/tests/V3toV4/Namespace_/Fixture/namespace_skip_x509.php.inc
new file mode 100644
index 0000000..b5bc58c
--- /dev/null
+++ b/tests/V3toV4/Namespace_/Fixture/namespace_skip_x509.php.inc
@@ -0,0 +1,31 @@
+<?php
+
+use phpseclib3\File\X509;
+use phpseclib3\Crypt\Random;
+
+class NamespaceSkipX509Class
+{
+    public function foo(): void
+    {
+        $x509 = new \phpseclib3\File\X509();
+        $r = \phpseclib3\Crypt\Random::string(16);
+    }
+}
+
+?>
+-----
+<?php
+
+use phpseclib3\File\X509;
+use phpseclib3\Crypt\Random;
+
+class NamespaceSkipX509Class
+{
+    public function foo(): void
+    {
+        $x509 = new \phpseclib3\File\X509();
+        $r = \phpseclib3\Crypt\Random::string(16);
+    }
+}
+
+?>
diff --git a/tests/V3toV4/Namespace_/Fixture/namespace_use.php.inc b/tests/V3toV4/Namespace_/Fixture/namespace_use.php.inc
new file mode 100644
index 0000000..0cca908
--- /dev/null
+++ b/tests/V3toV4/Namespace_/Fixture/namespace_use.php.inc
@@ -0,0 +1,39 @@
+<?php
+
+use phpseclib3\Crypt\RSA;
+use phpseclib3\Crypt\EC;
+use phpseclib3\Net\SFTP;
+use phpseclib3\Math\BigInteger;
+
+class NamespaceUseClass
+{
+    public function foo(): void
+    {
+        $key = RSA::createKey();
+        $ecKey = EC::createKey('nistp256');
+        $sftp = new SFTP('example.com');
+        $n = new BigInteger(42);
+    }
+}
+
+?>
+-----
+<?php
+
+use phpseclib4\Crypt\RSA;
+use phpseclib4\Crypt\EC;
+use phpseclib4\Net\SFTP;
+use phpseclib4\Math\BigInteger;
+
+class NamespaceUseClass
+{
+    public function foo(): void
+    {
+        $key = RSA::createKey();
+        $ecKey = EC::createKey('nistp256');
+        $sftp = new SFTP('example.com');
+        $n = new BigInteger(42);
+    }
+}
+
+?>
diff --git a/tests/V3toV4/Namespace_/Namespace_Test.php b/tests/V3toV4/Namespace_/Namespace_Test.php
new file mode 100644
index 0000000..3d7d138
--- /dev/null
+++ b/tests/V3toV4/Namespace_/Namespace_Test.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\V3toV4\Namespace_;
+
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class Namespace_Test extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): \Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/rule.php';
+    }
+}
diff --git a/tests/V3toV4/Namespace_/config/rule.php b/tests/V3toV4/Namespace_/config/rule.php
new file mode 100644
index 0000000..ad0f9cf
--- /dev/null
+++ b/tests/V3toV4/Namespace_/config/rule.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use phpseclib\rectorRules\Rector\V3toV4\Namespace_;
+
+return RectorConfig::configure()
+  ->withRules([Namespace_::class]);
diff --git a/tests/V3toV4/SFTPChmod/Fixture/sftp_chmod.php.inc b/tests/V3toV4/SFTPChmod/Fixture/sftp_chmod.php.inc
new file mode 100644
index 0000000..16ef268
--- /dev/null
+++ b/tests/V3toV4/SFTPChmod/Fixture/sftp_chmod.php.inc
@@ -0,0 +1,29 @@
+<?php
+
+use phpseclib4\Net\SFTP;
+
+class SFTPChmodClass
+{
+    public function foo(SFTP $sftp): void
+    {
+        $sftp->chmod(0777, 'filename.remote');
+        $sftp->chmod(0755, 'dirname', true);
+    }
+}
+
+?>
+-----
+<?php
+
+use phpseclib4\Net\SFTP;
+
+class SFTPChmodClass
+{
+    public function foo(SFTP $sftp): void
+    {
+        $sftp->chmod('filename.remote', 0777);
+        $sftp->chmod('dirname', 0755, true);
+    }
+}
+
+?>
diff --git a/tests/V3toV4/SFTPChmod/Fixture/sftp_chmod_skip.php.inc b/tests/V3toV4/SFTPChmod/Fixture/sftp_chmod_skip.php.inc
new file mode 100644
index 0000000..5338149
--- /dev/null
+++ b/tests/V3toV4/SFTPChmod/Fixture/sftp_chmod_skip.php.inc
@@ -0,0 +1,29 @@
+<?php
+
+use phpseclib4\Net\SFTP;
+
+// Already in v4 order (path first) — should not be changed
+class SFTPChmodSkipClass
+{
+    public function foo(SFTP $sftp): void
+    {
+        $sftp->chmod('filename.remote', 0777);
+    }
+}
+
+?>
+-----
+<?php
+
+use phpseclib4\Net\SFTP;
+
+// Already in v4 order (path first) — should not be changed
+class SFTPChmodSkipClass
+{
+    public function foo(SFTP $sftp): void
+    {
+        $sftp->chmod('filename.remote', 0777);
+    }
+}
+
+?>
diff --git a/tests/V3toV4/SFTPChmod/SFTPChmodTest.php b/tests/V3toV4/SFTPChmod/SFTPChmodTest.php
new file mode 100644
index 0000000..393d33b
--- /dev/null
+++ b/tests/V3toV4/SFTPChmod/SFTPChmodTest.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\V3toV4\SFTPChmod;
+
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class SFTPChmodTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): \Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/rule.php';
+    }
+}
diff --git a/tests/V3toV4/SFTPChmod/config/rule.php b/tests/V3toV4/SFTPChmod/config/rule.php
new file mode 100644
index 0000000..c6b7928
--- /dev/null
+++ b/tests/V3toV4/SFTPChmod/config/rule.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use phpseclib\rectorRules\Rector\V3toV4\SFTPChmod;
+
+return RectorConfig::configure()
+  ->withRules([SFTPChmod::class]);
diff --git a/tests/V3toV4/X509/Fixture/CRL_load_CRL-fullyqualified.php.inc b/tests/V3toV4/X509/Fixture/CRL_load_CRL-fullyqualified.php.inc
index 4017adb..d78e051 100644
--- a/tests/V3toV4/X509/Fixture/CRL_load_CRL-fullyqualified.php.inc
+++ b/tests/V3toV4/X509/Fixture/CRL_load_CRL-fullyqualified.php.inc
@@ -18,6 +18,6 @@ final class SomeClass
 {
   function foo()
   {
-    $crl = CRL::loadCRL(file_get_contents('crl.bin'));
+    $crl = CRL::load(file_get_contents('crl.bin'));
   }
 }
diff --git a/tests/V3toV4/X509/Fixture/CRL_load_CRL.php.inc b/tests/V3toV4/X509/Fixture/CRL_load_CRL.php.inc
index 9d5cabb..8839161 100644
--- a/tests/V3toV4/X509/Fixture/CRL_load_CRL.php.inc
+++ b/tests/V3toV4/X509/Fixture/CRL_load_CRL.php.inc
@@ -21,7 +21,7 @@ final class SomeClass
 {
   function foo()
   {
-    $crl = CRL::loadCRL(file_get_contents('crl.bin'));
+    $crl = CRL::load(file_get_contents('crl.bin'));
   }
 }
 
diff --git a/tests/V3toV4/X509/Fixture/CSR_load.php.inc b/tests/V3toV4/X509/Fixture/CSR_load.php.inc
index cec3268..fa1c30e 100644
--- a/tests/V3toV4/X509/Fixture/CSR_load.php.inc
+++ b/tests/V3toV4/X509/Fixture/CSR_load.php.inc
@@ -21,7 +21,7 @@ final class SomeClass
 {
   public function foo()
   {
-    $csr = CSR::loadCSR(file_get_contents('csr.csr'));
+    $csr = CSR::load(file_get_contents('csr.csr'));
   }
 }
 
diff --git a/tests/V3toV4/X509/Fixture/CSR_load_fullyqualified.php.inc b/tests/V3toV4/X509/Fixture/CSR_load_fullyqualified.php.inc
index 2bd4c7b..67c8e67 100644
--- a/tests/V3toV4/X509/Fixture/CSR_load_fullyqualified.php.inc
+++ b/tests/V3toV4/X509/Fixture/CSR_load_fullyqualified.php.inc
@@ -18,6 +18,6 @@ final class SomeClass
 {
   function foo()
   {
-    $csr = CSR::loadCSR(file_get_contents('csr.csr'));
+    $csr = CSR::load(file_get_contents('csr.csr'));
   }
 }
diff --git a/tests/V3toV4/X509/Fixture/CSR_setDnProp.php.inc b/tests/V3toV4/X509/Fixture/CSR_setDnProp.php.inc
index b82764d..b31be85 100644
--- a/tests/V3toV4/X509/Fixture/CSR_setDnProp.php.inc
+++ b/tests/V3toV4/X509/Fixture/CSR_setDnProp.php.inc
@@ -18,7 +18,7 @@ use phpseclib4\File\CSR;
 
 class SetDNPropClass {
   public static function SetDNProp() {
-    $csr = CSR::loadCSR(file_get_contents('csr.csr'));
+    $csr = CSR::load(file_get_contents('csr.csr'));
     $csr->addDNProp('id-at-organizationName', 'phpseclib CA cert');
   }
 }
diff --git a/tests/V3toV4/X509/Fixture/SPKAC_create-fullyqualified.php.inc b/tests/V3toV4/X509/Fixture/SPKAC_create-fullyqualified.php.inc
index 08b82f8..6f51ee8 100644
--- a/tests/V3toV4/X509/Fixture/SPKAC_create-fullyqualified.php.inc
+++ b/tests/V3toV4/X509/Fixture/SPKAC_create-fullyqualified.php.inc
@@ -15,12 +15,12 @@ final class SomeClass
 -----
 <?php
 
-use phpseclib4\File\CRL;
+use phpseclib4\File\SPKAC;
 final class SomeClass
 {
   public function foo()
   {
-    $spkac = CRL::loadCRL($privKey->getPublicKey());
+    $spkac = new SPKAC($privKey->getPublicKey());
     $spkac->setChallenge('123456789');
     $privKey->sign($spkac);
   }
diff --git a/tests/V3toV4/X509/Fixture/SPKAC_create.php.inc b/tests/V3toV4/X509/Fixture/SPKAC_create.php.inc
index ac6b45f..ed0ed72 100644
--- a/tests/V3toV4/X509/Fixture/SPKAC_create.php.inc
+++ b/tests/V3toV4/X509/Fixture/SPKAC_create.php.inc
@@ -17,13 +17,13 @@ final class SomeClass
 -----
 <?php
 
-use phpseclib4\File\CRL;
+use phpseclib4\File\SPKAC;
 
 final class SomeClass
 {
   public function foo()
   {
-    $spkac = CRL::loadCRL($privKey->getPublicKey());
+    $spkac = new SPKAC($privKey->getPublicKey());
     $spkac->setChallenge('123456789');
     $privKey->sign($spkac);
   }
diff --git a/tests/V3toV4/X509/Fixture/SPKAC_load_SPKAC-fullyqualified.php.inc b/tests/V3toV4/X509/Fixture/SPKAC_load_SPKAC-fullyqualified.php.inc
index b888582..6671681 100644
--- a/tests/V3toV4/X509/Fixture/SPKAC_load_SPKAC-fullyqualified.php.inc
+++ b/tests/V3toV4/X509/Fixture/SPKAC_load_SPKAC-fullyqualified.php.inc
@@ -13,11 +13,11 @@ final class SomeClass
 -----
 <?php
 
-use phpseclib4\File\CRL;
+use phpseclib4\File\SPKAC;
 final class SomeClass
 {
   function foo()
   {
-    $spkac = CRL::loadCRL(file_get_contents('spkac.txt'));
+    $spkac = SPKAC::load(file_get_contents('spkac.txt'));
   }
 }
diff --git a/tests/V3toV4/X509/Fixture/SPKAC_load_SPKAC.php.inc b/tests/V3toV4/X509/Fixture/SPKAC_load_SPKAC.php.inc
index b2f6352..2cb2e2b 100644
--- a/tests/V3toV4/X509/Fixture/SPKAC_load_SPKAC.php.inc
+++ b/tests/V3toV4/X509/Fixture/SPKAC_load_SPKAC.php.inc
@@ -15,13 +15,13 @@ final class SomeClass
 -----
 <?php
 
-use phpseclib4\File\CRL;
+use phpseclib4\File\SPKAC;
 
 final class SomeClass
 {
   public function foo()
   {
-    $spkac = CRL::loadCRL(file_get_contents('spkac.txt'));
+    $spkac = SPKAC::load(file_get_contents('spkac.txt'));
   }
 }
 
diff --git a/tests/V3toV4/X509/Fixture/SPKAC_setChallenge.php.inc b/tests/V3toV4/X509/Fixture/SPKAC_setChallenge.php.inc
index 6ff93d6..0e39f4d 100644
--- a/tests/V3toV4/X509/Fixture/SPKAC_setChallenge.php.inc
+++ b/tests/V3toV4/X509/Fixture/SPKAC_setChallenge.php.inc
@@ -14,13 +14,13 @@ final class SPKACSetChallenge
 ?>
 -----
 <?php
-use phpseclib4\File\CRL;
+use phpseclib4\File\SPKAC;
 
 final class SPKACSetChallenge
 {
   public function foo()
   {
-    $spkac = CRL::loadCRL($privKey->getPublicKey());
+    $spkac = new SPKAC($privKey->getPublicKey());
     $spkac->setChallenge('123456789');
   }
 }
diff --git a/tests/V3toV4/X509/Fixture/SPKAC_sign.php.inc b/tests/V3toV4/X509/Fixture/SPKAC_sign.php.inc
index ef4b882..003ded2 100644
--- a/tests/V3toV4/X509/Fixture/SPKAC_sign.php.inc
+++ b/tests/V3toV4/X509/Fixture/SPKAC_sign.php.inc
@@ -16,13 +16,13 @@ final class SPKACSignClass
 -----
 <?php
 
-use phpseclib4\File\CRL;
+use phpseclib4\File\SPKAC;
 
 final class SPKACSignClass
 {
   public function foo()
   {
-    $spkac = CRL::loadCRL($privKey->getPublicKey());
+    $spkac = new SPKAC($privKey->getPublicKey());
     $privKey->sign($spkac);
   }
 }
diff --git a/tests/V3toV4/X509/config/rule.php b/tests/V3toV4/X509/config/rule.php
index 1d277f3..26a84c7 100644
--- a/tests/V3toV4/X509/config/rule.php
+++ b/tests/V3toV4/X509/config/rule.php
@@ -4,9 +4,7 @@
 
 use Rector\Config\RectorConfig;
 
-use phpseclib\rectorRules\Rector\V3toV4\X509NodeVisitor;
 use phpseclib\rectorRules\Rector\V3toV4\X509;
 
 return RectorConfig::configure()
-  ->registerDecoratingNodeVisitor(X509NodeVisitor::class)
   ->withRules([X509::class]);