diff --git a/ChangeLog b/ChangeLog
index 0c43cd83..1b76b011 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,18 @@
 2012-07-15  Jay Berkenbilt  <ejb@ql.org>
 
+	* add new QPDF::isEncrypted method that returns some additional
+	information beyond other versions.
+
+	* libqpdf/QPDFWriter.cc: fix copyEncryptionParameters to fix the
+	minimum PDF version based on other file's encryption needs.  This
+	is a fix to code added on 2012-07-14 and did not impact previously
+	released code.
+
 	* libqpdf/QPDFWriter.cc (copyEncryptionParameters): Bug fix: qpdf
 	was not preserving whether or not AES encryption was being used
-	when copying encryption parameters.
+	when copying encryption parameters.  The file would still have
+	been properly encrypted, but a file that started off encrypted
+	with AES could have become encrypted with RC4.
 
 2012-07-14  Jay Berkenbilt  <ejb@ql.org>
 
diff --git a/TODO b/TODO
index d38cb002..6c8e043e 100644
--- a/TODO
+++ b/TODO
@@ -64,9 +64,11 @@ Next
     - Tests through qpdf command line: copy pages from multiple PDFs
       starting with one PDF and also starting with empty.
 
- * qpdf commandline: provide an option to copy encryption parameters
-   from another file, specifying file and password.  Search for "Copy
-   encryption parameters" in qpdf.test.
+ * Document --copy-encryption and --encryption-file-password in
+   manual.  Mention that the first half of /ID as well as all the
+   encryption parameters are copied.  Maybe mention about StrF and
+   StrM with respect to AES here and also with encryption
+   preservation.
 
 
 Soon
diff --git a/include/qpdf/QPDF.hh b/include/qpdf/QPDF.hh
index 4c8ede86..3b72e981 100644
--- a/include/qpdf/QPDF.hh
+++ b/include/qpdf/QPDF.hh
@@ -248,6 +248,12 @@ class QPDF
     QPDF_DLL
     bool isEncrypted(int& R, int& P);
 
+    QPDF_DLL
+    bool isEncrypted(int& R, int& P, int& V,
+                     encryption_method_e& stream_method,
+                     encryption_method_e& string_method,
+                     encryption_method_e& file_method);
+
     // Encryption permissions -- not enforced by QPDF
     QPDF_DLL
     bool allowAccessibility();
diff --git a/libqpdf/QPDF_encryption.cc b/libqpdf/QPDF_encryption.cc
index ee5d5685..c73a47bf 100644
--- a/libqpdf/QPDF_encryption.cc
+++ b/libqpdf/QPDF_encryption.cc
@@ -743,6 +743,17 @@ QPDF::isEncrypted() const
 
 bool
 QPDF::isEncrypted(int& R, int& P)
+{
+    int V;
+    encryption_method_e stream, string, file;
+    return isEncrypted(R, P, V, stream, string, file);
+}
+
+bool
+QPDF::isEncrypted(int& R, int& P, int& V,
+                  encryption_method_e& stream_method,
+                  encryption_method_e& string_method,
+                  encryption_method_e& file_method)
 {
     if (this->encrypted)
     {
@@ -750,8 +761,13 @@ QPDF::isEncrypted(int& R, int& P)
 	QPDFObjectHandle encrypt = trailer.getKey("/Encrypt");
 	QPDFObjectHandle Pkey = encrypt.getKey("/P");
 	QPDFObjectHandle Rkey = encrypt.getKey("/R");
+        QPDFObjectHandle Vkey = encrypt.getKey("/V");
 	P = Pkey.getIntValue();
 	R = Rkey.getIntValue();
+        V = Vkey.getIntValue();
+        stream_method = this->cf_stream;
+        string_method = this->cf_stream;
+        file_method = this->cf_file;
 	return true;
     }
     else
diff --git a/qpdf/qpdf.cc b/qpdf/qpdf.cc
index 148dff04..cf99ca44 100644
--- a/qpdf/qpdf.cc
+++ b/qpdf/qpdf.cc
@@ -33,18 +33,29 @@ Usage: qpdf [ options ] infilename [ outfilename ]\n\
 \n\
 An option summary appears below.  Please see the documentation for details.\n\
 \n\
+Note that when contradictory options are provided, whichever options are\n\
+provided last take precedence.\n\
+\n\
 \n\
 Basic Options\n\
 -------------\n\
 \n\
 --password=password     specify a password for accessing encrypted files\n\
 --linearize             generated a linearized (web optimized) file\n\
+--copy-encryption=file  copy encryption parameters from specified file\n\
+--encryption-file-password=password\n\
+                        password used to open the file from which encryption\n\
+                        parameters are being copied\n\
 --encrypt options --    generate an encrypted file\n\
 --decrypt               remove any encryption on the file\n\
 \n\
-If neither --encrypt or --decrypt are given, qpdf will preserve any\n\
-encryption data associated with a file.\n\
+If none of --copy-encryption, --encrypt or --decrypt are given, qpdf will\n\
+preserve any encryption data associated with a file.\n\
 \n\
+Note that when copying encryption parameters from another file, all\n\
+parameters will be copied, including both user and owner passwords, even\n\
+if the user password is used to open the other file.  This works even if\n\
+the owner password is not known.\n\
 \n\
 Encryption Options\n\
 ------------------\n\
@@ -192,12 +203,39 @@ static std::string show_bool(bool v)
     return v ? "allowed" : "not allowed";
 }
 
+static std::string show_encryption_method(QPDF::encryption_method_e method)
+{
+    std::string result = "unknown";
+    switch (method)
+    {
+      case QPDF::e_none:
+        result = "none";
+        break;
+      case QPDF::e_unknown:
+        result = "unknown";
+        break;
+      case QPDF::e_rc4:
+        result = "RC4";
+        break;
+      case QPDF::e_aes:
+        result = "AESv2";
+        break;
+        // no default so gcc will warn for missing case
+    }
+    return result;
+}
+
 static void show_encryption(QPDF& pdf)
 {
     // Extract /P from /Encrypt
     int R = 0;
     int P = 0;
-    if (! pdf.isEncrypted(R, P))
+    int V = 0;
+    QPDF::encryption_method_e stream_method = QPDF::e_unknown;
+    QPDF::encryption_method_e string_method = QPDF::e_unknown;
+    QPDF::encryption_method_e file_method = QPDF::e_unknown;
+    if (! pdf.isEncrypted(R, P, V,
+                          stream_method, string_method, file_method))
     {
 	std::cout << "File is not encrypted" << std::endl;
     }
@@ -206,25 +244,34 @@ static void show_encryption(QPDF& pdf)
 	std::cout << "R = " << R << std::endl;
 	std::cout << "P = " << P << std::endl;
 	std::string user_password = pdf.getTrimmedUserPassword();
-	std::cout << "User password = " << user_password << std::endl;
-	std::cout << "extract for accessibility: "
-		  << show_bool(pdf.allowAccessibility()) << std::endl;
-	std::cout << "extract for any purpose: "
-		  << show_bool(pdf.allowExtractAll()) << std::endl;
-	std::cout << "print low resolution: "
-		  << show_bool(pdf.allowPrintLowRes()) << std::endl;
-	std::cout << "print high resolution: "
-		  << show_bool(pdf.allowPrintHighRes()) << std::endl;
-	std::cout << "modify document assembly: "
-		  << show_bool(pdf.allowModifyAssembly()) << std::endl;
-	std::cout << "modify forms: "
-		  << show_bool(pdf.allowModifyForm()) << std::endl;
-	std::cout << "modify annotations: "
-		  << show_bool(pdf.allowModifyAnnotation()) << std::endl;
-	std::cout << "modify other: "
-		  << show_bool(pdf.allowModifyOther()) << std::endl;
-	std::cout << "modify anything: "
+	std::cout << "User password = " << user_password << std::endl
+                  << "extract for accessibility: "
+		  << show_bool(pdf.allowAccessibility()) << std::endl
+                  << "extract for any purpose: "
+		  << show_bool(pdf.allowExtractAll()) << std::endl
+                  << "print low resolution: "
+		  << show_bool(pdf.allowPrintLowRes()) << std::endl
+                  << "print high resolution: "
+		  << show_bool(pdf.allowPrintHighRes()) << std::endl
+                  << "modify document assembly: "
+		  << show_bool(pdf.allowModifyAssembly()) << std::endl
+                  << "modify forms: "
+		  << show_bool(pdf.allowModifyForm()) << std::endl
+                  << "modify annotations: "
+		  << show_bool(pdf.allowModifyAnnotation()) << std::endl
+                  << "modify other: "
+		  << show_bool(pdf.allowModifyOther()) << std::endl
+                  << "modify anything: "
 		  << show_bool(pdf.allowModifyAll()) << std::endl;
+        if (V >= 4)
+        {
+            std::cout << "stream encryption method: "
+                      << show_encryption_method(stream_method) << std::endl
+                      << "string encryption method: "
+                      << show_encryption_method(string_method) << std::endl
+                      << "file encryption method: "
+                      << show_encryption_method(file_method) << std::endl;
+        }
     }
 }
 
@@ -579,6 +626,10 @@ int main(int argc, char* argv[])
     bool linearize = false;
     bool decrypt = false;
 
+    bool copy_encryption = false;
+    char const* encryption_file = 0;
+    char const* encryption_file_password = "";
+
     bool encrypt = false;
     std::string user_password;
     std::string owner_password;
@@ -664,11 +715,36 @@ int main(int argc, char* argv[])
 		    r3_accessibility, r3_extract, r3_print, r3_modify,
 		    force_V4, cleartext_metadata, use_aes);
 		encrypt = true;
+                decrypt = false;
+                copy_encryption = false;
 	    }
 	    else if (strcmp(arg, "decrypt") == 0)
 	    {
 		decrypt = true;
+                encrypt = false;
+                copy_encryption = false;
 	    }
+            else if (strcmp(arg, "copy-encryption") == 0)
+            {
+		if (parameter == 0)
+		{
+		    usage("--copy-encryption must be given as"
+			  "--copy_encryption=file");
+		}
+                encryption_file = parameter;
+                copy_encryption = true;
+                encrypt = false;
+                decrypt = false;
+            }
+            else if (strcmp(arg, "encryption-file-password") == 0)
+            {
+		if (parameter == 0)
+		{
+		    usage("--encryption-file-password must be given as"
+			  "--encryption-file-password=password");
+		}
+                encryption_file_password = parameter;
+            }
 	    else if (strcmp(arg, "stream-data") == 0)
 	    {
 		if (parameter == 0)
@@ -865,6 +941,7 @@ int main(int argc, char* argv[])
     try
     {
 	QPDF pdf;
+        QPDF encryption_pdf;
 	if (ignore_xref_streams)
 	{
 	    pdf.setIgnoreXRefStreams(true);
@@ -1082,6 +1159,12 @@ int main(int argc, char* argv[])
 	    {
 		w.setSuppressOriginalObjectIDs(true);
 	    }
+            if (copy_encryption)
+            {
+                encryption_pdf.processFile(
+                    encryption_file, encryption_file_password);
+                w.copyEncryptionParameters(encryption_pdf);
+            }
 	    if (encrypt)
 	    {
 		if (keylen == 40)
diff --git a/qpdf/qtest/qpdf.test b/qpdf/qtest/qpdf.test
index 8687d713..1b979724 100644
--- a/qpdf/qtest/qpdf.test
+++ b/qpdf/qtest/qpdf.test
@@ -1271,7 +1271,7 @@ $td->runtest("linearize and encrypt file",
 	      $td->EXIT_STATUS => 0});
 $td->runtest("check encryption",
 	     {$td->COMMAND => "qpdf --show-encryption --password=owner a.pdf",
-	      $td->FILTER => "grep -v allowed"},
+	      $td->FILTER => "grep -v allowed | grep -v method"},
 	     {$td->STRING => "R = 4\nP = -4\nUser password = user\n",
 	      $td->EXIT_STATUS => 0},
 	     $td->NORMALIZE_NEWLINES);
@@ -1290,7 +1290,7 @@ $td->runtest("encrypt with AES",
 	     {$td->STRING => "", $td->EXIT_STATUS => 0});
 $td->runtest("check encryption",
 	     {$td->COMMAND => "qpdf --show-encryption a.pdf",
-	      $td->FILTER => "grep -v allowed"},
+	      $td->FILTER => "grep -v allowed | grep -v method"},
 	     {$td->STRING => "R = 4\nP = -4\nUser password = \n",
 	      $td->EXIT_STATUS => 0},
 	     $td->NORMALIZE_NEWLINES);
@@ -1311,7 +1311,7 @@ $td->runtest("linearize with AES and object streams",
 	     {$td->STRING => "", $td->EXIT_STATUS => 0});
 $td->runtest("check encryption",
 	     {$td->COMMAND => "qpdf --show-encryption a.pdf",
-	      $td->FILTER => "grep -v allowed"},
+	      $td->FILTER => "grep -v allowed | grep -v method"},
 	     {$td->STRING => "R = 4\nP = -4\nUser password = \n",
 	      $td->EXIT_STATUS => 0},
 	     $td->NORMALIZE_NEWLINES);
@@ -1345,7 +1345,7 @@ $td->runtest("make sure there is no xref stream",
 	     $td->NORMALIZE_NEWLINES);
 
 # Look at some actual V4 files
-$n_tests += 10;
+$n_tests += 14;
 foreach my $d (['--force-V4', 'V4'],
 	       ['--cleartext-metadata', 'V4-clearmeta'],
 	       ['--use-aes=y', 'V4-aes'],
@@ -1359,6 +1359,10 @@ foreach my $d (['--force-V4', 'V4'],
     $td->runtest("check output",
 		 {$td->FILE => "a.pdf"},
 		 {$td->FILE => "$out.pdf"});
+    $td->runtest("show encryption",
+		 {$td->COMMAND => "qpdf --show-encryption a.pdf"},
+		 {$td->FILE => "$out-encryption.out", $td->EXIT_STATUS => 0},
+                 $td->NORMALIZE_NEWLINES);
 }
 # Crypt Filter
 $td->runtest("decrypt with crypt filter",
@@ -1370,7 +1374,11 @@ $td->runtest("check output",
 	     {$td->FILE => 'decrypted-crypt-filter.pdf'});
 
 # Copy encryption parameters
-$n_tests += 3;
+$n_tests += 10;
+$td->runtest("create reference qdf",
+             {$td->COMMAND =>
+                  "qpdf --qdf --no-original-object-ids minimal.pdf a.qdf"},
+             {$td->STRING => "", $td->EXIT_STATUS => 0});
 $td->runtest("create encrypted file",
 	     {$td->COMMAND =>
 		  "qpdf --encrypt user owner 128 --use-aes=y --extract=n --" .
@@ -1380,11 +1388,42 @@ $td->runtest("copy encryption parameters",
              {$td->COMMAND => "test_driver 30 minimal.pdf a.pdf"},
              {$td->STRING => "test 30 done\n", $td->EXIT_STATUS => 0},
              $td->NORMALIZE_NEWLINES);
-$td->runtest("checkout encryption",
+$td->runtest("check output encryption",
 	     {$td->COMMAND => "qpdf --show-encryption b.pdf --password=owner"},
 	     {$td->FILE => "copied-encryption.out",
 	      $td->EXIT_STATUS => 0},
              $td->NORMALIZE_NEWLINES);
+$td->runtest("convert to qdf",
+             {$td->COMMAND =>
+                  "qpdf --qdf b.pdf b.qdf" .
+                  " --password=owner --no-original-object-ids"},
+             {$td->STRING => "", $td->EXIT_STATUS => 0});
+$td->runtest("compare qdf",
+             {$td->COMMAND => "./diff-ignore-ID-version a.qdf b.qdf"},
+             {$td->STRING => "okay\n", $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+$td->runtest("copy encryption with qpdf",
+             {$td->COMMAND =>
+                  "qpdf --copy-encryption=a.pdf".
+                  " --encryption-file-password=user" .
+                  " minimal.pdf c.pdf"},
+             {$td->STRING => "", $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+$td->runtest("check output encryption",
+	     {$td->COMMAND => "qpdf --show-encryption c.pdf --password=owner"},
+	     {$td->FILE => "copied-encryption.out",
+	      $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+$td->runtest("convert to qdf",
+             {$td->COMMAND =>
+                  "qpdf --qdf c.pdf c.qdf" .
+                  " --password=owner --no-original-object-ids"},
+             {$td->STRING => "", $td->EXIT_STATUS => 0});
+$td->runtest("compare qdf",
+             {$td->COMMAND => "./diff-ignore-ID-version a.qdf c.qdf"},
+             {$td->STRING => "okay\n", $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+
 
 show_ntests();
 # ----------
@@ -1753,6 +1792,5 @@ sub get_md5_checksum
 
 sub cleanup
 {
-    system("rm -rf *.ps *.pnm a.pdf a.qdf b.pdf b.qdf c.pdf" .
-	   " *.enc* tif1 tif2 tiff-cache");
+    system("rm -rf *.ps *.pnm ?.pdf ?.qdf *.enc* tif1 tif2 tiff-cache");
 }
diff --git a/qpdf/qtest/qpdf/V4-aes-clearmeta-encryption.out b/qpdf/qtest/qpdf/V4-aes-clearmeta-encryption.out
new file mode 100644
index 00000000..928818dc
--- /dev/null
+++ b/qpdf/qtest/qpdf/V4-aes-clearmeta-encryption.out
@@ -0,0 +1,15 @@
+R = 4
+P = -4
+User password = 
+extract for accessibility: allowed
+extract for any purpose: allowed
+print low resolution: allowed
+print high resolution: allowed
+modify document assembly: allowed
+modify forms: allowed
+modify annotations: allowed
+modify other: allowed
+modify anything: allowed
+stream encryption method: AESv2
+string encryption method: AESv2
+file encryption method: AESv2
diff --git a/qpdf/qtest/qpdf/V4-aes-encryption.out b/qpdf/qtest/qpdf/V4-aes-encryption.out
new file mode 100644
index 00000000..928818dc
--- /dev/null
+++ b/qpdf/qtest/qpdf/V4-aes-encryption.out
@@ -0,0 +1,15 @@
+R = 4
+P = -4
+User password = 
+extract for accessibility: allowed
+extract for any purpose: allowed
+print low resolution: allowed
+print high resolution: allowed
+modify document assembly: allowed
+modify forms: allowed
+modify annotations: allowed
+modify other: allowed
+modify anything: allowed
+stream encryption method: AESv2
+string encryption method: AESv2
+file encryption method: AESv2
diff --git a/qpdf/qtest/qpdf/V4-clearmeta-encryption.out b/qpdf/qtest/qpdf/V4-clearmeta-encryption.out
new file mode 100644
index 00000000..157fb8da
--- /dev/null
+++ b/qpdf/qtest/qpdf/V4-clearmeta-encryption.out
@@ -0,0 +1,15 @@
+R = 4
+P = -4
+User password = 
+extract for accessibility: allowed
+extract for any purpose: allowed
+print low resolution: allowed
+print high resolution: allowed
+modify document assembly: allowed
+modify forms: allowed
+modify annotations: allowed
+modify other: allowed
+modify anything: allowed
+stream encryption method: RC4
+string encryption method: RC4
+file encryption method: RC4
diff --git a/qpdf/qtest/qpdf/V4-encryption.out b/qpdf/qtest/qpdf/V4-encryption.out
new file mode 100644
index 00000000..157fb8da
--- /dev/null
+++ b/qpdf/qtest/qpdf/V4-encryption.out
@@ -0,0 +1,15 @@
+R = 4
+P = -4
+User password = 
+extract for accessibility: allowed
+extract for any purpose: allowed
+print low resolution: allowed
+print high resolution: allowed
+modify document assembly: allowed
+modify forms: allowed
+modify annotations: allowed
+modify other: allowed
+modify anything: allowed
+stream encryption method: RC4
+string encryption method: RC4
+file encryption method: RC4
diff --git a/qpdf/qtest/qpdf/copied-encryption.out b/qpdf/qtest/qpdf/copied-encryption.out
index 6db6fa63..cbec2305 100644
--- a/qpdf/qtest/qpdf/copied-encryption.out
+++ b/qpdf/qtest/qpdf/copied-encryption.out
@@ -10,3 +10,6 @@ modify forms: allowed
 modify annotations: allowed
 modify other: allowed
 modify anything: allowed
+stream encryption method: AESv2
+string encryption method: AESv2
+file encryption method: AESv2
diff --git a/qpdf/qtest/qpdf/diff-ignore-ID-version b/qpdf/qtest/qpdf/diff-ignore-ID-version
new file mode 100755
index 00000000..e6b33470
--- /dev/null
+++ b/qpdf/qtest/qpdf/diff-ignore-ID-version
@@ -0,0 +1,8 @@
+#!/bin/sh
+lines=$(expr + $(diff $1 $2 | egrep '^[<>]' | \
+        egrep -v '/ID' | egrep -v '%PDF-' | wc -l))
+if [ "$lines" = "0" ]; then
+   echo okay
+else
+   diff -a -U 0 $1 $2
+fi
diff --git a/qpdf/test_driver.cc b/qpdf/test_driver.cc
index 518e5569..3d2f0dca 100644
--- a/qpdf/test_driver.cc
+++ b/qpdf/test_driver.cc
@@ -58,12 +58,17 @@ class Provider: public QPDFObjectHandle::StreamDataProvider
     bool bad_length;
 };
 
-static void checkPageContents(QPDFObjectHandle page,
-                              std::string const& wanted_string)
+static std::string getPageContents(QPDFObjectHandle page)
 {
     PointerHolder<Buffer> b1 =
         page.getKey("/Contents").getStreamData();
-    std::string contents = std::string((char *)(b1->getBuffer()));
+    return std::string((char *)(b1->getBuffer()), b1->getSize()) + "\0";
+}
+
+static void checkPageContents(QPDFObjectHandle page,
+                              std::string const& wanted_string)
+{
+    std::string contents = getPageContents(page);
     if (contents.find(wanted_string) == std::string::npos)
     {
         std::cout << "didn't find " << wanted_string << " in "
@@ -1030,10 +1035,24 @@ void runtest(int n, char const* filename1, char const* filename2)
         QPDF encrypted;
         encrypted.processFile(filename2, "user");
         QPDFWriter w(pdf, "b.pdf");
-	w.setStaticID(true);
 	w.setStreamDataMode(qpdf_s_preserve);
         w.copyEncryptionParameters(encrypted);
 	w.write();
+
+        // Make sure the contents are actually the same
+        QPDF final;
+        final.processFile("b.pdf", "user");
+        std::vector<QPDFObjectHandle> pages = pdf.getAllPages();
+        std::string orig_contents = getPageContents(pages[0]);
+        pages = final.getAllPages();
+        std::string new_contents = getPageContents(pages[0]);
+        if (orig_contents != new_contents)
+        {
+            std::cout << "oops -- page contents don't match" << std::endl
+                      << "original:\n" << orig_contents
+                      << "new:\n" << new_contents
+                      << std::endl;
+        }
     }
     else
     {