diff --git a/xorriso/xorriso.1 b/xorriso/xorriso.1
index 5ab2835d..866705c5 100644
--- a/xorriso/xorriso.1
+++ b/xorriso/xorriso.1
@@ -2,7 +2,7 @@
 .\" First parameter, NAME, should be all caps
 .\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
 .\" other parameters are allowed: see man(7), man(1)
-.TH XORRISO 1 "Aug 09, 2009"
+.TH XORRISO 1 "Aug 10, 2009"
 .\" Please adjust this date whenever revising the manpage.
 .\"
 .\" Some roff macros, for reference:
@@ -750,6 +750,14 @@ same filesystems. Use this if mode "on" always sees all files changed.
 The speed advantage appears only if the loaded session was produced with
 -disk_dev_ino "on" too.
 .TP
+\fB\-md5\fR "on"|"off"
+Enable or disable processing of MD5 checksums for the overall session and for
+each single data file. If enabled then MD5 checksums get loaded from the image
+if there are any. At image generation time they are computed for each file
+which gets its data written into the new session. The checksums of files which
+have their data in older sessions get copied into the new session.
+For now checksums can be exploited only via find action get_md5.
+.TP
 \fB\-rom_toc_scan\fR "on"|"off"[:"emul_on"|"emul_off"]
 Read-only drives do not tell the actual media type but show any media as
 ROM (e.g. as DVD-ROM). The session history of MMC multi-session media might
diff --git a/xorriso/xorriso.c b/xorriso/xorriso.c
index e28cd932..1f0742f9 100644
--- a/xorriso/xorriso.c
+++ b/xorriso/xorriso.c
@@ -5265,6 +5265,7 @@ int Xorriso_new(struct XorrisO ** xorriso,char *progname, int flag)
  m->ino_behavior= 7;
  m->do_joliet= 0;
  m->do_aaip= 0;
+ m->do_md5= 0;
  m->relax_compliance= 0;
  m->do_follow_pattern= 1;
  m->do_follow_param= 0;
@@ -7664,6 +7665,11 @@ int Xorriso_status(struct XorrisO *xorriso, char *filter, FILE *fp, int flag)
  if(!(is_default && no_defaults))
    Xorriso_status_result(xorriso,filter,fp,flag&2);
 
+ is_default= ((xorriso->do_md5 & (1 | 2 | 4)) == 0);
+ sprintf(line,"-md5 %s\n", (xorriso->do_md5 & 1 ? "on" : "off"));
+ if(!(is_default && no_defaults))
+   Xorriso_status_result(xorriso,filter,fp,flag&2);
+
  is_default= (Xorriso_get_relax_text(xorriso, sfe, 0) == 2);
  sprintf(line,"-compliance %s\n", sfe);
  if(!(is_default && no_defaults))
@@ -11226,6 +11232,7 @@ int Xorriso_genisofs(struct XorrisO *xorriso, char *whom,
 "  --hardlinks                 Record eventual hard link relations of files",
 "  --acl                       Record eventual ACLs of files",
 "  --xattr                     Record eventual user space xattr of files",
+"  --md5                       Compute and record MD5 checksums of data files",
 "  -V ID, -volid ID            Set Volume ID",
 "  -b FILE, -eltorito-boot FILE",
 "                              Set El Torito boot image name",
@@ -11387,6 +11394,8 @@ int Xorriso_genisofs(struct XorrisO *xorriso, char *whom,
      Xorriso_option_acl(xorriso, "on", 0);
    } else if(strcmp(argv[i], "--xattr")==0) {
      Xorriso_option_xattr(xorriso, "on", 0);
+   } else if(strcmp(argv[i], "--md5")==0) {
+     Xorriso_option_md5(xorriso, "on", 0);
    } else if(strcmp(argv[i], "-z")==0 ||
              strcmp(argv[i], "-transparent-compression")==0) {
      Xorriso_option_zisofs(xorriso, "by_magic=on", 0);
@@ -11600,6 +11609,8 @@ not_enough_args:;
      /* was already handled in first argument scan */;
    } else if(strcmp(argv[i], "--xattr")==0) {
      /* was already handled in first argument scan */;
+   } else if(strcmp(argv[i], "--md5")==0) {
+     /* was already handled in first argument scan */;
    } else if(strcmp(argv[i], "-z")==0 ||
              strcmp(argv[i], "-transparent-compression")==0) {
      /* was already handled in first argument scan */;
@@ -15840,6 +15851,8 @@ int Xorriso_option_help(struct XorrisO *xorriso, int flag)
 "  -disk_dev_ino \"on\"|\"ino_only\"|\"off\"",
 "                 Enable resp. disable recording of disk file dev_t and ino_t",
 "                 and their use in file comparison.",
+"  -md5 \"on\"|\"off\"",
+"                 Enable resp. disable processing of MD5 checksums.",
 "  -ban_stdio_write",
 "                 Allow for writing only the usage of optical drives.",
 "  -blank \"fast\"|\"all\"|\"deformat\"|\"deformat_quickest\"",
@@ -16885,6 +16898,22 @@ int Xorriso_option_mark(struct XorrisO *xorriso, char *mark, int flag)
 }
 
 
+/* Option -md5 "on"|"off" */
+int Xorriso_option_md5(struct XorrisO *xorriso, char *mode, int flag)
+{
+ if(strcmp(mode, "off")==0)
+   xorriso->do_md5&= ~7;
+ else if(strcmp(mode, "on")==0)
+   xorriso->do_md5|= (1 | 2 | 4);
+ else {
+   sprintf(xorriso->info_text, "-md5: unknown mode '%s'", mode);
+   Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FAILURE", 0);
+   return(0);
+ }
+ return(1);
+}
+
+
 /* Option -mkdir alias -mkdiri */
 int Xorriso_option_mkdiri(struct XorrisO *xorriso, int argc, char **argv,
                           int *idx, int flag)
@@ -19014,7 +19043,7 @@ int Xorriso_count_args(struct XorrisO *xorriso, int argc, char **argv,
     "dev","dialog","disk_dev_ino","disk_pattern","dummy","eject",
     "iso_rr_pattern","follow","format","fs","gid","grow_blindly","hardlinks",
     "history","indev","in_charset","joliet","list_delimiter","local_charset",
-    "mark","not_leaf","not_list","not_mgt",
+    "mark","md5","not_leaf","not_list","not_mgt",
     "options_from_file","osirrox","outdev","out_charset","overwrite",
     "pacifier","padding","path_list","pathspecs","pkt_output","print","prompt",
     "prog","prog_help","publisher","quoted_not_list","quoted_path_list",
@@ -19518,6 +19547,10 @@ next_command:;
    (*idx)++;
    ret= Xorriso_option_mark(xorriso, arg1, 0);
 
+ } else if(strcmp(cmd, "md5")==0) {
+   (*idx)++;
+   ret= Xorriso_option_md5(xorriso, arg1, 0);
+
  } else if(strcmp(cmd, "mount") == 0 || strcmp(cmd, "mount_cmd") == 0) {
    (*idx)+= 4;
    if((*idx)>argc) {
diff --git a/xorriso/xorriso_private.h b/xorriso/xorriso_private.h
index 2fa327c0..55fdfeca 100644
--- a/xorriso/xorriso_private.h
+++ b/xorriso/xorriso_private.h
@@ -124,6 +124,11 @@ struct XorrisO { /* the global context of xorriso */
                  bit9= allow to set input charset from xattr "isofs.cs"
               */
 
+ int do_md5;  /* bit0= read MD5 array
+                 bit1= write session MD5
+                 bit2= wite MD5 for each data file
+               */
+
  int relax_compliance;        /* opaque bitfield to be set by xorrisoburn */
  int do_follow_pattern;
  int do_follow_param;
@@ -835,6 +840,7 @@ struct ExprtesT {
   11= -decision char *arg1 ("yes", "no")
   12= -prune
   13= -wholename char *arg1 (regex_t in *arg2)
+  14= -has_any_xattr
  */
  int test_type;
 
@@ -936,6 +942,8 @@ struct FindjoB {
    30= internal: count by xorriso->node_counter
    31= internal: register in xorriso->node_array
    32= internal: widen_hardlinks disk_equiv: update nodes marked in di_do_widen
+   33= get_any_xattr
+   34= get_md5
  */
  int action;
  int prune;
diff --git a/xorriso/xorriso_timestamp.h b/xorriso/xorriso_timestamp.h
index 5f88786b..020121be 100644
--- a/xorriso/xorriso_timestamp.h
+++ b/xorriso/xorriso_timestamp.h
@@ -1 +1 @@
-#define Xorriso_timestamP "2009.08.10.192240"
+#define Xorriso_timestamP "2009.08.10.193843"
diff --git a/xorriso/xorrisoburn.c b/xorriso/xorrisoburn.c
index 77a63297..4dc34edc 100644
--- a/xorriso/xorrisoburn.c
+++ b/xorriso/xorrisoburn.c
@@ -1122,10 +1122,12 @@ int Xorriso_aquire_drive(struct XorrisO *xorriso, char *adr, int flag)
    ext|= isoburn_ropt_noacl; 
  if(!(xorriso->do_aaip & 4))
    ext|= isoburn_ropt_noea; 
-
-#ifdef isoburn_ropt_noino
- if (xorriso->ino_behavior & 1)
+ if(xorriso->ino_behavior & 1)
    ext|= isoburn_ropt_noino;
+
+#ifdef isoburn_ropt_nomd5
+ if(!(xorriso->do_md5 & 1))
+   ext|= isoburn_ropt_nomd5;
 #endif
 
  isoburn_ropt_set_extensions(ropts, ext);
@@ -1787,7 +1789,11 @@ int Xorriso_write_session(struct XorrisO *xorriso, int flag)
       ((!!xorriso->do_joliet) * isoburn_igopt_joliet) |
       (( !(xorriso->ino_behavior & 2)) * isoburn_igopt_hardlinks) |
       (( (!(xorriso->ino_behavior & 2)) ||
-         (xorriso->do_aaip & (2 | 8 | 16 | 256))) * isoburn_igopt_aaip);
+         (xorriso->do_aaip & (2 | 8 | 16 | 256)) ||
+         (xorriso->do_md5 & (2 | 4))
+       ) * isoburn_igopt_aaip) |
+      ((!!(xorriso->do_md5 & 2)) * isoburn_igopt_session_md5) |
+      ((!!(xorriso->do_md5 & 4)) * isoburn_igopt_file_md5);
  isoburn_igopt_set_extensions(sopts, ext);
  isoburn_igopt_set_relaxed(sopts, relax);
  isoburn_igopt_set_sort_files(sopts, 1);