diff --git a/.gitmodules b/.gitmodules
index ce35a4d..e960fc7 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "src/Qt-AES"]
 	path = src/Qt-AES
 	url = https://github.com/QuasarApp/Qt-AES.git
+[submodule "src/mini-gmp"]
+	path = src/mini-gmp
+	url = https://github.com/QuasarApp/mini-gmp.git
diff --git a/Qt-Secret.pro b/Qt-Secret.pro
index 03329c3..3bebc71 100644
--- a/Qt-Secret.pro
+++ b/Qt-Secret.pro
@@ -8,13 +8,16 @@
 TEMPLATE = subdirs
 CONFIG += ordered
 
-SUBDIRS += src \
+SUBDIRS += \
+           minigmp \
+           src \
            tests \
            qaesencryption
 
 include($$PWD/test.pri)
 VERSION = 1.1.0
 
+minigmp.file = src/mini-gmp/GMP.pro
 src.file = src/Qt-Secret.pro
 tests.file = tests/Qt-SecretTest.pro
 qaesencryption.file = src/Qt-AES/qaesencryption.pro
diff --git a/src/Qt-RSA/qrsaencryption.cpp b/src/Qt-RSA/qrsaencryption.cpp
index aa0a72d..2ce59de 100644
--- a/src/Qt-RSA/qrsaencryption.cpp
+++ b/src/Qt-RSA/qrsaencryption.cpp
@@ -7,6 +7,8 @@
 
 #include "qrsaencryption.h"
 
+#include <bigint.h>
+
 typedef unsigned __int128  uint128_t;
 typedef signed __int128  int128_t;
 
@@ -118,7 +120,7 @@ template<class INT>
 INT toPrime(INT n) {
 
     if (!(n % 2)) {
-        n++;
+        ++n;
     }
 
     INT LN = n;
@@ -204,7 +206,7 @@ bool keyGenerator(QByteArray &pubKey, QByteArray &privKey) {
     INT eilor = eulerFunc(p, q);
     INT e = randNumber<INT>() % eilor;
 
-    if (!(e % 2)) e--;
+    if (!(e % 2)) --e;
 
     do {
         e -= 2;
@@ -344,6 +346,14 @@ bool QRSAEncryption::generatePairKey(QByteArray &pubKey, QByteArray &privKey, QR
                 }
                 break;
             }
+            case RSA_256: {
+                if (!keyGenerator<BigInt>(pubKey, privKey)) {
+                    return false;
+                }
+                break;
+            }
+        default:
+            break;
         }
 
     } while (!(keyGenRes = testKeyPair(pubKey, privKey)) && (++cnt < KEY_GEN_LIMIT));
diff --git a/src/Qt-RSA/qrsaencryption.h b/src/Qt-RSA/qrsaencryption.h
index b78ac70..d935234 100644
--- a/src/Qt-RSA/qrsaencryption.h
+++ b/src/Qt-RSA/qrsaencryption.h
@@ -29,7 +29,11 @@ class QRSAEncryption
 public:
     enum Rsa {
         RSA_64 = 64,
-        RSA_128 = 128
+        RSA_128 = 128,
+        RSA_256 = 256,
+        RSA_512 = 512,
+        RSA_1024 = 1024,
+        RSA_2048 = 2048
     };
 
     QRSAEncryption();
diff --git a/src/Qt-Secret.pro b/src/Qt-Secret.pro
index 0496e0d..c814519 100644
--- a/src/Qt-Secret.pro
+++ b/src/Qt-Secret.pro
@@ -21,6 +21,8 @@ CONFIG(release, debug|release): {
     DESTDIR="$$PWD/build/debug"
 }
 
+include($$PWD/mini-gmp/GMP.pri)
+
 VERSION = 1.1.0
 
 HEADERS += Qt-AES/qaesencryption.h \
diff --git a/src/mini-gmp b/src/mini-gmp
new file mode 160000
index 0000000..fa777cc
--- /dev/null
+++ b/src/mini-gmp
@@ -0,0 +1 @@
+Subproject commit fa777ccb252daa4c1b4ea766ea86e6ad37ba2590