diff --git a/firmware/applications/final.c b/firmware/applications/final.c
index 7cb1054..d9ee29a 100644
--- a/firmware/applications/final.c
+++ b/firmware/applications/final.c
@@ -18,9 +18,12 @@ void forLoadables(int i){
     if(i){
         lcdSetPixel(0,0);
         font=&Font_Invaders;
-        filetransfer_send();
+        //filetransfer_send();
         ECIES_encyptkeygen();
-        filetransfer_receive();
+        //filetransfer_receive();
+        //rftransfer_receive(); 
+        //rftransfer_send(); 
+        systickGetTicks();
         ECIES_decryptkeygen();
         bitstr_parse_export();
         nrf_rcv_pkt_time_encr();
diff --git a/firmware/loadable/avcard.c b/firmware/loadable/avcard.c
deleted file mode 100644
index f879168..0000000
--- a/firmware/loadable/avcard.c
+++ /dev/null
@@ -1,299 +0,0 @@
-#include <sysinit.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <stdint.h>
-#include "basic/basic.h"
-#include "lcd/render.h"
-#include "lcd/allfonts.h"
-#include "basic/ecc.h"
-#include "funk/nrf24l01p.h"
-#include "filesystem/ff.h"
-#include "filesystem/diskio.h"
-#include "funk/filetransfer.h"
-#include "lcd/print.h"
-
-
-
-uint8_t mac[5] = {1,2,3,2,1};
-
-void sendPublicKey(void)
-{
-    uint8_t exp[2 + 4*NUMWORDS + 2];
-    char buf[42];
-    UINT readbytes;
-    FIL file;
-
-    if( f_open(&file, "pubx.key", FA_OPEN_EXISTING|FA_READ) ){
-        return;
-    }
-    if( f_read(&file, buf, 41, &readbytes) || readbytes != 41 ){
-        return;
-    }
-    f_close(&file);
-    buf[41] = 0;
-
-    exp[0] = 'P';
-    bitstr_parse_export((char*)exp+2, buf);
-    exp[1] = 'X';
-    nrf_snd_pkt_crc(32, exp);
-    delayms(10);
-
-    if( f_open(&file, "puby.key", FA_OPEN_EXISTING|FA_READ) ){
-        return;
-    }
-    if( f_read(&file, buf, 41, &readbytes) || readbytes != 41 ){
-        return;
-    }
-    f_close(&file);
-    buf[41] = 0;
-
-    exp[1] = 'Y';
-    bitstr_parse_export((char*)exp+2, buf);
-    nrf_snd_pkt_crc(32, exp);
-    delayms(10);
-}
-
-void sendR(uint8_t *rx, uint8_t *ry)
-{
-    uint8_t exp[2 + 4*NUMWORDS + 2];
-    exp[0] = 'R';
-    for(int i=0; i<4*NUMWORDS; i++)
-        exp[2+i] = rx[i];
-    exp[1] = 'X';
-    nrf_snd_pkt_crc(32, exp);
-    delayms(10);
-    exp[1] = 'Y';
-    for(int i=0; i<4*NUMWORDS; i++)
-        exp[2+i] = ry[i]; 
-    nrf_snd_pkt_crc(32, exp);
-    delayms(10);
-}
-
-int receiveKey(uint8_t type, uint8_t *x, uint8_t *y)
-{
-    uint8_t buf[32];
-    uint8_t n;
-    
-    n = nrf_rcv_pkt_time(1000, 32, buf);
-    if( n == 32 && buf[0] == type && buf[1] == 'X' ){
-        for(int i=0; i<NUMWORDS*4; i++)
-            x[i] = buf[i+2];
-        n = nrf_rcv_pkt_time(100, 32, buf);
-        if( n == 32 && buf[0] ==type && buf[1] == 'Y' ){
-            for(int i=0; i<NUMWORDS*4; i++)
-                y[i] = buf[i+2];
-            return 0;
-        }
-    }
-    return -1;
-}
-
-int receivePublicKey(uint8_t *px, uint8_t *py)
-{
-    return receiveKey('P',px,py);
-}
-
-int receiveR(uint8_t *rx, uint8_t *ry)
-{
-    return receiveKey('R',rx,ry);
-}
-
-void sendMac(void)
-{
-    uint8_t buf[32];
-    buf[0] = 'M';
-    buf[1] = 'C';
-    buf[2] = mac[0];
-    buf[3] = mac[1];
-    buf[4] = mac[2];
-    buf[5] = mac[3];
-    buf[6] = mac[4];
-    nrf_snd_pkt_crc(32, buf);
-    delayms(10);
-}
-
-int receiveMac(uint8_t *mac)
-{
-    uint8_t buf[32]; 
-    uint8_t n;
-
-    n = nrf_rcv_pkt_time(100, 32, buf);
-    if( n == 32 && buf[0] == 'M' && buf[1] == 'C' ){
-        for(int i=0; i<5; i++)
-            mac[i] = buf[i+2];
-        return 0;
-    }
-    return -1;
-}
-
-int sendKeys(void)
-{
-    uint8_t done = 0;
-    char key;
-    while( !done ){
-        lcdClear();
-        lcdPrintln("Sending PUBKEY");lcdRefresh();
-        sendPublicKey();
-        sendMac();
-        lcdPrintln("Done");
-        lcdPrintln("Right=OK");
-        lcdPrintln("Left=Retry");
-        lcdPrintln("Down=Abort");
-        lcdRefresh();
-
-        while(1){
-            key = getInput();
-            delayms(20);
-            if( key == BTN_LEFT ){
-                break;
-            }else if( key == BTN_RIGHT ){
-                done = 1;
-                break;
-            }else if( key == BTN_DOWN ){
-                return -1;
-            }
-        }
-    }
-    return 0;
-}
-int receiveKeys(uint8_t *px, uint8_t *py, uint8_t *mac)
-{
-    uint8_t done = 0;
-    char key;
-    while( !done ){
-        lcdClear();
-        lcdPrintln("Recv. PUBKEY");
-        lcdPrintln("Down=Abort");
-        lcdRefresh();
-        key = getInput();
-        delayms(20);
-        if( key == BTN_DOWN ){
-            return -1;
-        }
-        if( receivePublicKey(px,py) )
-            continue;
-        if( receiveMac(mac) )
-            continue;
-        lcdClear();
-        lcdPrintln("Got PUBKEY"); lcdRefresh(); 
-        lcdPrintln("Hash:");
-        lcdPrintln("Right=OK");
-        lcdPrintln("Left=Retry");
-        lcdPrintln("Down=Abort");
-        lcdRefresh();
-        while(1){
-            key = getInput();
-            delayms(20);
-            if( key == BTN_LEFT ){
-                break;
-            }else if( key == BTN_RIGHT ){
-                done = 1;
-                break;
-            }else if( key == BTN_DOWN ){
-                return -1;
-            }
-        }
-    }
-    return 0;
-}
-
-void receiveFile(void)
-{
-    if( sendKeys() )
-        return;
-
-    char priv[42];
-    UINT readbytes;
-    FIL file;
-
-    if( f_open(&file, "priv.key", FA_OPEN_EXISTING|FA_READ) ){
-        return;
-    }
-    if( f_read(&file, priv, 41, &readbytes) || readbytes != 41 ){
-        return;
-    }
-    f_close(&file);
-    priv[41] = 0;
-
-    uint8_t done = 0;
-    uint8_t key;
-    uint8_t k1[16], k2[16], rx[4*NUMWORDS], ry[4*NUMWORDS];
- 
-    while( !done ){
-        lcdClear();
-        lcdPrintln("Receiving file");
-        lcdPrintln("Down=Abort");
-        lcdRefresh();
-        key = getInput();
-        delayms(20);
-        if( key == BTN_DOWN ){
-            return -1;
-        }
-        if( receiveR(rx,ry) )
-            continue;
-        lcdPrintln("Creating key");
-        lcdRefresh();
-        ECIES_decryptkeygen(rx, ry, k1, k2, priv);
-        if( filetransfer_receive(mac,(uint32_t*)k1) < 0 )
-            continue;
-        lcdPrintln("Right=OK");
-        lcdPrintln("Left=Retry");
-        lcdPrintln("Down=Abort");
-        lcdRefresh();
-
-        while(1){
-            key = getInput();
-            delayms(20);
-            if( key == BTN_LEFT ){
-                break;
-            }else if( key == BTN_RIGHT ){
-                done = 1;
-                break;
-            }else if( key == BTN_DOWN ){
-                return -1;
-            }
-        }
-    }
-}
-
-void sendFile(char *filename)
-{
-    uint8_t px[4*NUMWORDS];
-    uint8_t py[4*NUMWORDS];
-    uint8_t mac[5];
-    if( receiveKeys(px, py, mac) )
-        return;
-    
-    uint8_t done = 0;
-    uint8_t key;
-
-    uint8_t k1[16], k2[16], rx[4*NUMWORDS], ry[4*NUMWORDS];
-    
-    lcdClear();
-    lcdPrintln("Creating key"); lcdRefresh();
-    ECIES_encyptkeygen(px, py, k1, k2, rx, ry);
-    
-    while( !done ){
-        lcdPrintln("Sending file");lcdRefresh();
-        sendR(rx,ry);
-        delayms(3000);
-        filetransfer_send((uint8_t*)filename, 0, mac, (uint32_t*)k1);
-        lcdPrintln("Done");
-        lcdPrintln("Right=OK");
-        lcdPrintln("Left=Retry");
-        lcdRefresh();
-        while(1){
-            key = getInput();
-            delayms(20);
-            if( key == BTN_LEFT ){
-                break;
-            }else if( key == BTN_RIGHT ){
-                done = 1;
-                break;
-            }
-        } 
-        lcdClear();
-    }
-}
-
diff --git a/firmware/loadable/recvcard.c b/firmware/loadable/recvcard.c
index a5ed46f..57fad8b 100644
--- a/firmware/loadable/recvcard.c
+++ b/firmware/loadable/recvcard.c
@@ -180,4 +180,141 @@ int sendKeys(void)
     }
     return 0;
 }
+#include <string.h>
+#include "funk/nrf24l01p.h"
+#include "funk/filetransfer.h"
+#include "funk/rftransfer.h"
+#include "basic/basic.h"
+#include "basic/xxtea.h"
+#include "filesystem/ff.h"
+#include "lcd/print.h"
+
+
+int filetransfer_receive(uint8_t *mac, uint32_t const k[4])
+{
+    uint8_t buf[MAXSIZE+1];
+    uint16_t size;
+    uint8_t n;
+
+    UINT written = 0;
+    FIL file;
+    FRESULT res;
+    //uint8_t macbuf[5];
+    //nrf_get_rx_max(0,5,macbuf);
+
+    uint8_t metadata[32];
+
+    //nrf_set_rx_mac(0, 32, 5, mac);
+    n = nrf_rcv_pkt_time_encr(3000, 32, metadata, k);
+    if( n != 32 )
+        return 1;       //timeout
+    //nrf_set_rx_mac(0, 32, 5, macbuf);
+    //lcdPrintln("got meta"); lcdRefresh();
+    metadata[19] = 0; //enforce termination
+    size = (metadata[20] << 8) | metadata[21];
+
+    if( size > MAXSIZE ) {lcdPrintln("too big"); lcdRefresh(); while(1);}
+    if( size > MAXSIZE ) return 1; //file to big
+    //if(fileexists(metadata)) return 1;   //file already exists
+    
+    //lcdPrint("open"); lcdPrintln((const char*)metadata); lcdRefresh();
+    res = f_open(&file, (const char*)metadata, FA_OPEN_ALWAYS|FA_WRITE);
+
+    //lcdPrintln("file opened"); lcdRefresh();
+    if( res ) {lcdPrintln("res"); lcdPrint(f_get_rc_string(res)); lcdRefresh(); while(1);}
+    if( res )
+        return res;
+    
+    uint16_t wordcount = (size+3)/4;
+    
+    //nrf_set_rx_mac(0, 32, 5, mac);
+    //lcdPrintln("get file"); lcdRefresh();
+    int fres = rftransfer_receive(buf, wordcount*4, 1000);
+    if( fres == -1 ){
+        lcdPrintln("checksum wrong");
+    }else if( fres == -2 ){
+        lcdPrintln("timeout");
+    }else{
+        //lcdPrintln("got file");
+    }
+    lcdRefresh();
+    if( fres < 0 )
+        return 1;
+    //nrf_set_rx_mac(0, 32, 5, macbuf);
+
+    xxtea_decode_words((uint32_t *)buf, wordcount, k);
+    
+    res = f_write(&file, buf, size, &written);
+    f_close(&file);
+    if( res )
+        return res;
+    if( written != size )
+        return 1;           //error while writing
+    lcdClear();
+    lcdPrintln("Received"); lcdPrintln((const char*)metadata); lcdRefresh();
+
+    return 0;
+}
+
+#define MAXPACKET   32
+int16_t rftransfer_receive(uint8_t *buffer, uint16_t maxlen, uint16_t timeout)
+{
+    uint8_t buf[MAXPACKET];
+    uint8_t state = 0;
+    uint16_t pos = 0, seq = 0, size = 0, rand = 0, crc = 0;
+    int n,i;
+    unsigned int currentTick = systickGetTicks();
+    unsigned int startTick = currentTick;
+    
+    while(systickGetTicks() < (startTick+timeout) ){//this fails if either overflows
+        n = nrf_rcv_pkt_time(1000, MAXPACKET, buf);
+        switch(state){
+            case 0:
+                if( n == 32 && buf[0] == 'L' ){
+                    size = (buf[1] << 8) | buf[2];
+                    rand =  (buf[3] << 8) | buf[4];
+                    seq = 0;
+                    pos = 0;
+                    if( size <= maxlen ){
+                        //lcdClear();
+                        //lcdPrint("got l="); lcdPrintInt(size);
+                        //lcdPrintln(""); lcdRefresh();
+                        state = 1;
+                    }
+                }
+            break;
+            case 1:
+                if( n == 32 && buf[0] == 'D' && ((buf[3]<<8)|buf[4])==rand ){
+                    //lcdPrint("got d"); lcdRefresh();
+                    if( seq == ((buf[1]<<8)|buf[2]) ){
+                        //lcdPrintln(" in seq"); lcdRefresh();
+                            for(i=5; i<n-2 && pos<size; i++,pos++){
+                                buffer[pos] = buf[i];
+                            }
+                            seq++;
+                    }
+                }
+                if( pos == size ){
+                    //lcdPrintln("got all"); lcdRefresh();
+                    crc = crc16(buffer, size);
+                    state = 2;
+                }
+            break;
+            case 2:
+                if( n == 32 && buf[0] == 'C' && ((buf[3]<<8)|buf[4])==rand){
+                    //lcdPrint("got crc"); lcdRefresh();
+                    if( crc == ((buf[1]<<8)|buf[2]) ){
+                        //lcdPrintln(" ok"); lcdRefresh();
+                        return size;
+                    }else{
+                        //lcdPrintln(" nok"); lcdRefresh();
+                        return -1;
+                    }
+                }
+            break;
+        };
+    }
+    //lcdPrintln("Timeout"); lcdRefresh();
+    return -2;
+}
 
diff --git a/firmware/loadable/sendcard.c b/firmware/loadable/sendcard.c
index f210425..b31dae3 100644
--- a/firmware/loadable/sendcard.c
+++ b/firmware/loadable/sendcard.c
@@ -174,3 +174,111 @@ void sendFile(char *filename)
     }
 }
 
+#include <string.h>
+#include "funk/nrf24l01p.h"
+#include "funk/filetransfer.h"
+#include "funk/rftransfer.h"
+#include "basic/basic.h"
+#include "basic/xxtea.h"
+#include "filesystem/ff.h"
+#include "lcd/print.h"
+
+
+//TODO: use a proper MAC to sign the message
+int filetransfer_send(uint8_t *filename, uint16_t size,
+                uint8_t *mac, uint32_t const k[4])
+{
+    uint8_t buf[MAXSIZE];
+    FIL file;
+    FRESULT res;
+    UINT readbytes;
+
+
+    if( size > MAXSIZE )
+        return 1;           //File to big
+ 
+    res=f_open(&file, (const char*)filename, FA_OPEN_EXISTING|FA_READ);
+    if( res )
+        return res;
+
+    //res = f_read(&file, (char *)buf, size, &readbytes);
+    for(uint16_t i=0; i<MAXSIZE; i++)
+        buf[i] = 0;
+
+    res = f_read(&file, (char *)buf, MAXSIZE, &readbytes);
+    size = readbytes;
+
+    if( res )
+        return res;
+    if( size != readbytes)
+        return 1;           //Error while reading
+    
+    uint16_t wordcount = (size+3)/4;
+    //uint8_t macbuf[5];
+
+    uint8_t metadata[32];
+    if( strlen((char*)filename) < 20 )
+        strcpy((char*)metadata, (char*)filename);
+    else
+        return 1;           //File name too long
+    metadata[20] = size >> 8;
+    metadata[21] = size & 0xFF;
+
+    //nrf_get_tx_max(5,macbuf);
+
+    //nrf_set_tx_mac(5, mac); 
+    nrf_snd_pkt_crc_encr(32, metadata, k); 
+    delayms(20);
+    xxtea_encode_words((uint32_t *)buf, wordcount, k);
+    rftransfer_send(wordcount*4, buf);
+    //nrf_set_tx_mac(5, macbuf);
+    return 0;
+}
+
+#include "funk/rftransfer.h"
+#include "funk/nrf24l01p.h"
+#include <basic/basic.h>
+#include <basic/random.h>
+#include <core/systick/systick.h>
+#include <lcd/print.h>
+
+#define MAXPACKET   32
+void rftransfer_send(uint16_t size, uint8_t *data)
+{
+    uint8_t buf[MAXPACKET];
+    buf[0] = 'L';
+    buf[1] = size >> 8;
+    buf[2] = size & 0xFF;
+
+    uint16_t rand = getRandom() & 0xFFFF;
+    buf[3] = rand >> 8;
+    buf[4] = rand & 0xFF;
+
+    nrf_snd_pkt_crc(32,buf);     //setup packet
+    delayms(20);
+    uint16_t index = 0;
+    uint8_t i;
+    uint16_t crc = crc16(data,size);
+
+    while(size){
+        buf[0] = 'D';
+        buf[1] = index >> 8;
+        buf[2] = index & 0xFF;
+        buf[3] = rand >> 8;
+        buf[4] = rand & 0xFF;
+        for(i=5; i<MAXPACKET-2 && size>0; i++,size--){
+            buf[i] = *data++;
+        }
+        index++;
+        nrf_snd_pkt_crc(32,buf);     //data packet
+        delayms(20);
+    }
+
+    buf[0] = 'C';
+    buf[1] = crc >> 8;
+    buf[2] = crc & 0xFF;
+    buf[3] = rand >> 8;
+    buf[4] = rand & 0xFF;
+    nrf_snd_pkt_crc(32,buf);     //setup packet
+    delayms(20);
+}