diff --git a/Makefile b/Makefile
index d713494b..0741b873 100644
--- a/Makefile
+++ b/Makefile
@@ -19,7 +19,7 @@ test: all
 	$(MAKE) -C test test
 
 package: clean
-	cd .. ; COPYFILE_DISABLE=true tar  cjf pEpEngine.tar.bz2 pEpEngine
+	cd .. ; COPYFILE_DISABLE=true tar cjf pEpEngine.tar.bz2 pEpEngine
 
 windist:
 ifneq ($(BUILD_FOR),Windoze)
diff --git a/Makefile.conf b/Makefile.conf
index 07605422..20f53c36 100644
--- a/Makefile.conf
+++ b/Makefile.conf
@@ -1,7 +1,7 @@
 BUILD_ON=$(shell uname)
 BUILD_FOR=$(BUILD_ON)
-OPTIMIZE=-g -O0
-#OPTIMIZE=-O3 -DNDEBUG
+#OPTIMIZE=-g -O0
+OPTIMIZE=-O3 -DNDEBUG
 # the next two lines are ignored on Windoze
 SYSTEM_DB=/usr/local/share/pEp/system.db
 PREFIX=$(HOME)
diff --git a/README.txt b/README.txt
index 90435add..989cda12 100644
--- a/README.txt
+++ b/README.txt
@@ -7,6 +7,8 @@ pEp Engine
 The pEp Engine encapsulates all real functionality of pEp.
 It has an old style Makefile for building it.
 
+The build is configured in Makefile.conf
+
 It supports the common targets
 
 $ make all
diff --git a/src/message_api.c b/src/message_api.c
new file mode 100644
index 00000000..307ad898
--- /dev/null
+++ b/src/message_api.c
@@ -0,0 +1,106 @@
+#include "message_api.h"
+#include "keymanagement.h"
+
+#include <libetpan/libetpan.h>
+#include <assert.h>
+#include <string.h>
+
+PEP_STATUS encrypt_message(
+        PEP_SESSION session,
+        const message *src,
+        stringlist_t * extra,
+        message **dst
+    )
+{
+    PEP_STATUS status = PEP_STATUS_OK;
+
+    assert(session);
+    assert(src);
+    assert(dst);
+    *dst = NULL;
+
+    message *msg = new_message(src->dir, src->from, src->to, NULL);
+    if (msg == NULL)
+        return PEP_OUT_OF_MEMORY;
+
+    src->from->me = true;
+
+    status = myself(session, src->from);
+    if (status != PEP_STATUS_OK) {
+        free_message(msg);
+        return status;
+    }
+
+    stringlist_t * keys = new_stringlist(src->from->fpr);
+    if (keys == NULL) {
+        free_message(msg);
+        return PEP_OUT_OF_MEMORY;
+    }
+
+    stringlist_t *_x;
+    for (_x = extra; _x && _x->value; _x = _x->next) {
+        if (stringlist_add(keys, _x->value) == NULL) {
+            free_message(msg);
+            free_stringlist(keys);
+            return PEP_OUT_OF_MEMORY;
+        }
+    }
+    
+    identity_list * _il;
+    for (_il = src->to; _il && _il->ident; _il = _il->next) {
+        status = update_identity(session, _il->ident);
+        if (status != PEP_STATUS_OK) {
+            free_message(msg);
+            free_stringlist(keys);
+            return status;
+        }
+        if (_il->ident->fpr) {
+            if (stringlist_add(keys, _il->ident->fpr) == NULL) {
+                free_message(msg);
+                free_stringlist(keys);
+                return PEP_OUT_OF_MEMORY;
+            }
+        }
+        else
+            status = PEP_KEY_NOT_FOUND;
+    }
+
+    int _own_keys = 1;
+    if (extra)
+        _own_keys += stringlist_length(extra);
+    
+    if (stringlist_length(keys) > _own_keys) {
+        char *ptext = NULL;
+        char *ctext = NULL;
+        size_t csize = 0;
+
+        // TODO: set ptext to MIME text
+
+        status = encrypt_and_sign(session, keys, ptext, strlen(ptext), &ctext, &csize);
+        if (ctext) {
+            msg->longmsg = ctext;
+            msg->longmsg_size = csize;
+            *dst = msg;
+        }
+        else
+            free_message(msg);
+        free(ptext);
+    }
+    else
+        free_message(msg);
+
+    free_stringlist(keys);
+    return status;
+}
+
+PEP_STATUS decrypt_message(
+        PEP_SESSION session,
+        const message *src,
+        message **dst
+    )
+{
+    PEP_STATUS status = PEP_STATUS_OK;
+
+    return status;
+}
+
diff --git a/src/message_api.h b/src/message_api.h
new file mode 100644
index 00000000..c4752b41
--- /dev/null
+++ b/src/message_api.h
@@ -0,0 +1,23 @@
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "transport.h"
+
+PEP_STATUS encrypt_message(
+        PEP_SESSION session,
+        const message *src,
+        stringlist_t *extra,
+        message **dst
+    );
+
+PEP_STATUS decrypt_message(
+        PEP_SESSION session,
+        const message *src,
+        message **dst
+    );
+
+#ifdef __cplusplus
+}
+#endif
+
diff --git a/src/pEpEngine.c b/src/pEpEngine.c
index fc1b4a84..5f0e7990 100644
--- a/src/pEpEngine.c
+++ b/src/pEpEngine.c
@@ -534,6 +534,24 @@ pEp_identity *new_identity(
     return result;
 }
 
+pEp_identity *identity_dup(const pEp_identity *src)
+{
+    assert(src);
+
+    pEp_identity *dup = new_identity(src->address, src->fpr, src->user_id, src->username);
+    assert(dup);
+    if (dup == NULL)
+        return NULL;
+    
+    dup->comm_type = src->comm_type;
+    dup->lang[0] = src->lang[0];
+    dup->lang[1] = src->lang[1];
+    dup->lang[2] = 0;
+    dup->me = src->me;
+
+    return dup;
+}
+
 void free_identity(pEp_identity *identity)
 {
     if (identity) {
diff --git a/src/pEpEngine.h b/src/pEpEngine.h
index dd8c8de7..390e1280 100644
--- a/src/pEpEngine.h
+++ b/src/pEpEngine.h
@@ -415,6 +415,21 @@ DYNAMIC_API pEp_identity *new_identity(
     );
 
 
+// identity_dup() - allocate memory and set the string and size fields
+//
+//  parameters:
+//      src (in)            identity to duplicate
+//
+//  return value:
+//      pEp_identity struct with correct size values or NULL if out of memory
+//
+//  caveat:
+//      the strings are copied; the original strings are still being owned by
+//      the caller
+
+DYNAMIC_API pEp_identity *identity_dup(const pEp_identity *src);
+
+
 // free_identity() - free all memory being occupied by a pEp_identity struct
 //
 //  parameters:
diff --git a/src/transport.c b/src/transport.c
index b8c53a14..83b938da 100644
--- a/src/transport.c
+++ b/src/transport.c
@@ -24,28 +24,6 @@ void release_transport_system(PEP_SESSION session)
     // nothing yet
 }
 
-pEp_identity *identity_dup(const pEp_identity *src)
-{
-    assert(src);
-
-    pEp_identity *dup = new_identity(src->address, src->fpr, src->user_id, src->username);
-    assert(dup);
-    if (dup == NULL)
-        return NULL;
-    
-    dup->address_size = strlen(dup->address);
-    dup->fpr_size = strlen(dup->fpr);
-    dup->user_id_size = strlen(dup->user_id);
-    dup->username_size = strlen(dup->username);
-    dup->comm_type = src->comm_type;
-    dup->lang[0] = src->lang[0];
-    dup->lang[1] = src->lang[1];
-    dup->lang[2] = 0;
-    dup->me = src->me;
-
-    return dup;
-}
-
 identity_list *new_identity_list(const pEp_identity *ident)
 {
     identity_list *id_list = calloc(1, sizeof(identity_list));
@@ -65,6 +43,26 @@ identity_list *new_identity_list(const pEp_identity *ident)
     return id_list;
 }
 
+identity_list *identity_list_dup(const identity_list *src)
+{
+    assert(src);
+
+    identity_list *id_list = new_identity_list(src->ident);
+    assert(id_list);
+    if (id_list == NULL)
+        return NULL;
+
+    if (src->next) {
+        id_list->next = identity_list_dup(src->next);
+        if (id_list->next == NULL) {
+            free_identity_list(id_list);
+            return NULL;
+        }
+    }
+
+    return id_list;
+}
+
 void free_identity_list(identity_list *id_list)
 {
     if (id_list) {
@@ -100,7 +98,7 @@ identity_list *identity_list_add(identity_list *id_list, const pEp_identity *ide
 message *new_message(
         msg_direction dir,
         const pEp_identity *from,
-        const pEp_identity *to,
+        const identity_list *to,
         const char *shortmsg
     )
 {
@@ -109,13 +107,15 @@ message *new_message(
     if (msg == NULL)
         return NULL;
 
-    msg->shortmsg = strdup(shortmsg);
-    assert(msg->shortmsg);
-    if (msg->shortmsg == NULL) {
-        free(msg);
-        return NULL;
+    if (msg->shortmsg) {
+        msg->shortmsg = strdup(shortmsg);
+        assert(msg->shortmsg);
+        if (msg->shortmsg == NULL) {
+            free(msg);
+            return NULL;
+        }
+        msg->shortmsg_size = strlen(msg->shortmsg);
     }
-    msg->shortmsg_size = strlen(msg->shortmsg);
 
     msg->dir = dir;
 
@@ -126,16 +126,7 @@ message *new_message(
         return NULL;
     }
 
-    if (dir == dir_incoming) {
-        msg->recv_by = identity_dup(to);
-        assert(msg->recv_by);
-        if (msg->recv_by == NULL) {
-            free_message(msg);
-            return NULL;
-        }
-    }
-
-    msg->to = new_identity_list(to);
+    msg->to = identity_list_dup(to);
     assert(msg->to);
     if (msg->to == NULL) {
         free_message(msg);
diff --git a/src/transport.h b/src/transport.h
index a69d87bd..07aeb6fc 100644
--- a/src/transport.h
+++ b/src/transport.h
@@ -4,9 +4,12 @@
 #include <time.h>
 #include <stdlib.h>
 
+// all functions are using POSIX struct tm
+
 typedef struct tm timestamp;
 
 typedef enum _PEP_transports {
+    // auto transport chooses transport per message automatically
     PEP_trans_auto = 0,
 //    PEP_trans_email,
 //    PEP_trans_whatsapp,
@@ -16,14 +19,13 @@ typedef enum _PEP_transports {
 
 typedef struct _PEP_transport_t PEP_transport_t;
 
-pEp_identity *identity_dup(const pEp_identity *src);
-
 typedef struct _identity_list {
     pEp_identity *ident;
     struct _identity_list *next;
 } identity_list;
 
 identity_list *new_identity_list(const pEp_identity *ident);
+identity_list *identity_list_dup(const identity_list *src);
 void free_identity_list(identity_list *id_list);
 identity_list *identity_list_add(identity_list *id_list, const pEp_identity *ident);
 
@@ -73,7 +75,7 @@ typedef struct _message_ref_list {
 message *new_message(
         msg_direction dir,
         const pEp_identity *from,
-        const pEp_identity *to,
+        const identity_list *to,
         const char *shortmsg
     );
 
@@ -98,3 +100,4 @@ typedef uint64_t transports_mask;
 
 PEP_STATUS init_transport_system(PEP_SESSION session);
 void release_transport_system(PEP_SESSION session);
+