diff --git a/client/src/mifare/desfirecrypto.c b/client/src/mifare/desfirecrypto.c
index 11b29b9db..355a60b26 100644
--- a/client/src/mifare/desfirecrypto.c
+++ b/client/src/mifare/desfirecrypto.c
@@ -311,7 +311,38 @@ void DesfireCryptoCMAC(DesfireContext *ctx, uint8_t *data, size_t len, uint8_t *
         memcpy(cmac, ctx->IV, kbs);
 }
 
+void DesfireDESKeySetVersion(uint8_t *key, DesfireCryptoAlgorythm keytype, uint8_t version) {
+    if (keytype == T_AES)
+        return;
 
+    // clear version
+    for (int n = 0; n < desfire_get_key_length(keytype); n++)
+        key[n] &= 0xFE;
+
+    // set version
+    for (int n = 0; n < 8; n++) {
+        uint8_t version_bit = ((version & (1 << (7 - n))) >> (7 - n));
+
+        key[n] &= 0xFE;
+        key[n] |= version_bit;
+
+        if (keytype == T_DES) {
+            key[n + 8] = key->data[n];
+        } else {
+            // Write ~version to avoid turning a 3DES key into a DES key
+            key->data[n + 8] &= 0xFE;
+            key->data[n + 8] |= ~version_bit;
+        }
+    }
+}
+
+uint8_t DesfireDESKeyGetVersion(uint8_t *key) {
+    uint8_t version = 0;
+    for (int n = 0; n < 8; n++) {
+        version = version << 1;
+        version |= (key[n] & 0xFE);
+    }
+}
 void desfire_crc32(const uint8_t *data, const size_t len, uint8_t *crc) {
     crc32_ex(data, len, crc);
 }
diff --git a/client/src/mifare/desfirecrypto.h b/client/src/mifare/desfirecrypto.h
index 6bffa376e..c83720d80 100644
--- a/client/src/mifare/desfirecrypto.h
+++ b/client/src/mifare/desfirecrypto.h
@@ -101,6 +101,9 @@ void DesfireCryptoEncDec(DesfireContext *ctx, bool use_session_key, uint8_t *src
 void DesfireCryptoEncDecEx(DesfireContext *ctx, bool use_session_key, uint8_t *srcdata, size_t srcdatalen, uint8_t *dstdata, bool encode, uint8_t *iv);
 void DesfireCryptoCMAC(DesfireContext *ctx, uint8_t *srcdata, size_t srcdatalen, uint8_t *cmac);
 
+void DesfireDESKeySetVersion(uint8_t *key, DesfireCryptoAlgorythm keytype, uint8_t version);
+uint8_t DesfireDESKeyGetVersion(uint8_t *key);
+
 void desfire_crc32(const uint8_t *data, const size_t len, uint8_t *crc);
 void desfire_crc32_append(uint8_t *data, const size_t len);
 bool desfire_crc32_check(uint8_t *data, const size_t len, uint8_t *crc);