diff --git a/GCryptLib/include/GCrypt/BlockMatrix.h b/GCryptLib/include/GCrypt/BlockMatrix.h
new file mode 100644
index 0000000..6f28a84
--- /dev/null
+++ b/GCryptLib/include/GCrypt/BlockMatrix.h
@@ -0,0 +1,49 @@
+#ifndef GCRYPT_BLOCKMATRIX_H
+#define GCRYPT_BLOCKMATRIX_H
+
+#include "GCrypt/Block.h"
+#include <cstdint>
+#include <array>
+
+namespace Leonetienne::GCrypt {
+
+  /* This class represents a block as a matrix,
+   * providing typical matrix operations
+  */
+  class BlockMatrix {
+    public:
+      BlockMatrix();
+      BlockMatrix(const Block& block);
+      BlockMatrix(const BlockMatrix& other);
+
+      //! Will calculate the product of two matrices.
+      //! Since the matrices values are pretty much sudo-random,
+      //! they will most likely integer-overflow.
+      //! So see this as a one-way function.
+      BlockMatrix MMult(const BlockMatrix& other) const;
+      BlockMatrix operator*(const BlockMatrix& other) const;
+
+      //! Will do a regular matrix-mult, but instead of
+      //! adding, and multiplying, all ints get xored.
+      BlockMatrix MXor(const BlockMatrix& other) const;
+
+      bool operator==(const BlockMatrix& other) const;
+      bool operator!=(const BlockMatrix& other) const;
+
+      void FromBlock(const Block& block);
+      Block ToBlock() const;
+
+    private:
+      //! Returns items of data, indexed by 4x4 coordinates
+      std::uint32_t& Get(const std::uint8_t row, const std::uint8_t column);
+      //! Returns items of data, indexed by 4x4 coordinates
+      const std::uint32_t& Get(const std::uint8_t row, const std::uint8_t column) const;
+
+      std::array<std::uint32_t, 16> data;
+  };
+
+}
+
+
+#endif
+
diff --git a/GCryptLib/include/GCrypt/Config.h b/GCryptLib/include/GCrypt/Config.h
index dd56656..0bcac82 100644
--- a/GCryptLib/include/GCrypt/Config.h
+++ b/GCryptLib/include/GCrypt/Config.h
@@ -8,7 +8,7 @@ namespace Leonetienne::GCrypt {
   constexpr std::size_t BLOCK_SIZE = 512;
 
   // MUST BE > 2
-  constexpr std::size_t N_ROUNDS = 400;
+  constexpr std::size_t N_ROUNDS = 10;
 }
 
 #endif
diff --git a/GCryptLib/include/GCrypt/Version.h b/GCryptLib/include/GCrypt/Version.h
index ff66ec4..256c32b 100644
--- a/GCryptLib/include/GCrypt/Version.h
+++ b/GCryptLib/include/GCrypt/Version.h
@@ -1,7 +1,7 @@
 #ifndef GCRYPT_VERSION_H
 #define GCRYPT_VERSION_H
 
-#define GCRYPT_VERSION 0.23
+#define GCRYPT_VERSION 0.231
 
 #endif
 
diff --git a/GCryptLib/src/BlockMatrix.cpp b/GCryptLib/src/BlockMatrix.cpp
new file mode 100644
index 0000000..e1915c9
--- /dev/null
+++ b/GCryptLib/src/BlockMatrix.cpp
@@ -0,0 +1,114 @@
+#include "GCrypt/BlockMatrix.h"
+#include <sstream>
+
+namespace Leonetienne::GCrypt {
+
+  BlockMatrix::BlockMatrix() {
+  }
+
+  BlockMatrix::BlockMatrix(const Block& block) {
+    FromBlock(block);
+  }
+
+  BlockMatrix::BlockMatrix(const BlockMatrix& other) {
+    data = other.data;
+  }
+
+  void BlockMatrix::FromBlock(const Block& block) {
+
+    const std::string blockstr = block.to_string();
+    constexpr std::size_t cellSize = sizeof(std::uint32_t)*8;
+
+    for (std::size_t i = 0; i < 16; i++) {
+      data[i] = std::bitset<cellSize>(blockstr.substr(i*cellSize, cellSize)).to_ulong();
+    }
+
+    return;
+  }
+
+  Block BlockMatrix::ToBlock() const {
+
+    std::stringstream ss;
+    constexpr std::size_t cellSize = sizeof(std::uint32_t)*8;
+
+    for (std::size_t i = 0; i < 16; i++) {
+      ss << std::bitset<cellSize>(data[i]).to_string();
+    }
+    return Block(ss.str());
+  }
+
+  BlockMatrix BlockMatrix::MMult(const BlockMatrix& o) const {
+
+    BlockMatrix m;
+
+    m.Get(0, 0) = (this->Get(0, 0) * o.Get(0, 0)) + (this->Get(0, 1) * o.Get(1, 0)) + (this->Get(0, 2) * o.Get(2, 0)) + (this->Get(0, 3) * o.Get(3, 0));
+    m.Get(0, 1) = (this->Get(0, 0) * o.Get(0, 1)) + (this->Get(0, 1) * o.Get(1, 1)) + (this->Get(0, 2) * o.Get(2, 1)) + (this->Get(0, 3) * o.Get(3, 1));
+    m.Get(0, 2) = (this->Get(0, 0) * o.Get(0, 2)) + (this->Get(0, 1) * o.Get(1, 2)) + (this->Get(0, 2) * o.Get(2, 2)) + (this->Get(0, 3) * o.Get(3, 2));
+    m.Get(0, 3) = (this->Get(0, 0) * o.Get(0, 3)) + (this->Get(0, 1) * o.Get(1, 3)) + (this->Get(0, 2) * o.Get(2, 3)) + (this->Get(0, 3) * o.Get(3, 3));
+
+    m.Get(1, 0) = (this->Get(1, 0) * o.Get(0, 0)) + (this->Get(1, 1) * o.Get(1, 0)) + (this->Get(1, 2) * o.Get(2, 0)) + (this->Get(1, 3) * o.Get(3, 0));
+    m.Get(1, 1) = (this->Get(1, 0) * o.Get(0, 1)) + (this->Get(1, 1) * o.Get(1, 1)) + (this->Get(1, 2) * o.Get(2, 1)) + (this->Get(1, 3) * o.Get(3, 1));
+    m.Get(1, 2) = (this->Get(1, 0) * o.Get(0, 2)) + (this->Get(1, 1) * o.Get(1, 2)) + (this->Get(1, 2) * o.Get(2, 2)) + (this->Get(1, 3) * o.Get(3, 2));
+    m.Get(1, 3) = (this->Get(1, 0) * o.Get(0, 3)) + (this->Get(1, 1) * o.Get(1, 3)) + (this->Get(1, 2) * o.Get(2, 3)) + (this->Get(1, 3) * o.Get(3, 3));
+
+    m.Get(2, 0) = (this->Get(2, 0) * o.Get(0, 0)) + (this->Get(2, 1) * o.Get(1, 0)) + (this->Get(2, 2) * o.Get(2, 0)) + (this->Get(2, 3) * o.Get(3, 0));
+    m.Get(2, 1) = (this->Get(2, 0) * o.Get(0, 1)) + (this->Get(2, 1) * o.Get(1, 1)) + (this->Get(2, 2) * o.Get(2, 1)) + (this->Get(2, 3) * o.Get(3, 1));
+    m.Get(2, 2) = (this->Get(2, 0) * o.Get(0, 2)) + (this->Get(2, 1) * o.Get(1, 2)) + (this->Get(2, 2) * o.Get(2, 2)) + (this->Get(2, 3) * o.Get(3, 2));
+    m.Get(2, 3) = (this->Get(2, 0) * o.Get(0, 3)) + (this->Get(2, 1) * o.Get(1, 3)) + (this->Get(2, 2) * o.Get(2, 3)) + (this->Get(2, 3) * o.Get(3, 3));
+
+    m.Get(3, 0) = (this->Get(3, 0) * o.Get(0, 0)) + (this->Get(3, 1) * o.Get(1, 0)) + (this->Get(3, 2) * o.Get(2, 0)) + (this->Get(3, 3) * o.Get(3, 0));
+    m.Get(3, 1) = (this->Get(3, 0) * o.Get(0, 1)) + (this->Get(3, 1) * o.Get(1, 1)) + (this->Get(3, 2) * o.Get(2, 1)) + (this->Get(3, 3) * o.Get(3, 1));
+    m.Get(3, 2) = (this->Get(3, 0) * o.Get(0, 2)) + (this->Get(3, 1) * o.Get(1, 2)) + (this->Get(3, 2) * o.Get(2, 2)) + (this->Get(3, 3) * o.Get(3, 2));
+    m.Get(3, 3) = (this->Get(3, 0) * o.Get(0, 3)) + (this->Get(3, 1) * o.Get(1, 3)) + (this->Get(3, 2) * o.Get(2, 3)) + (this->Get(3, 3) * o.Get(3, 3));
+
+    return m;
+  }
+
+  BlockMatrix BlockMatrix::operator*(const BlockMatrix& other) const {
+    return this->MMult(other);
+  }
+
+  BlockMatrix BlockMatrix::MXor(const BlockMatrix& o) const {
+
+    BlockMatrix m;
+
+    m.Get(0, 0) = this->Get(0, 0) ^ o.Get(0, 0) ^ this->Get(0, 1) ^ o.Get(1, 0) ^ this->Get(0, 2) ^ o.Get(2, 0) ^ this->Get(0, 3) ^ o.Get(3, 0);
+    m.Get(0, 1) = this->Get(0, 0) ^ o.Get(0, 1) ^ this->Get(0, 1) ^ o.Get(1, 1) ^ this->Get(0, 2) ^ o.Get(2, 1) ^ this->Get(0, 3) ^ o.Get(3, 1);
+    m.Get(0, 2) = this->Get(0, 0) ^ o.Get(0, 2) ^ this->Get(0, 1) ^ o.Get(1, 2) ^ this->Get(0, 2) ^ o.Get(2, 2) ^ this->Get(0, 3) ^ o.Get(3, 2);
+    m.Get(0, 3) = this->Get(0, 0) ^ o.Get(0, 3) ^ this->Get(0, 1) ^ o.Get(1, 3) ^ this->Get(0, 2) ^ o.Get(2, 3) ^ this->Get(0, 3) ^ o.Get(3, 3);
+
+    m.Get(1, 0) = this->Get(1, 0) ^ o.Get(0, 0) ^ this->Get(1, 1) ^ o.Get(1, 0) ^ this->Get(1, 2) ^ o.Get(2, 0) ^ this->Get(1, 3) ^ o.Get(3, 0);
+    m.Get(1, 1) = this->Get(1, 0) ^ o.Get(0, 1) ^ this->Get(1, 1) ^ o.Get(1, 1) ^ this->Get(1, 2) ^ o.Get(2, 1) ^ this->Get(1, 3) ^ o.Get(3, 1);
+    m.Get(1, 2) = this->Get(1, 0) ^ o.Get(0, 2) ^ this->Get(1, 1) ^ o.Get(1, 2) ^ this->Get(1, 2) ^ o.Get(2, 2) ^ this->Get(1, 3) ^ o.Get(3, 2);
+    m.Get(1, 3) = this->Get(1, 0) ^ o.Get(0, 3) ^ this->Get(1, 1) ^ o.Get(1, 3) ^ this->Get(1, 2) ^ o.Get(2, 3) ^ this->Get(1, 3) ^ o.Get(3, 3);
+
+    m.Get(2, 0) = this->Get(2, 0) ^ o.Get(0, 0) ^ this->Get(2, 1) ^ o.Get(1, 0) ^ this->Get(2, 2) ^ o.Get(2, 0) ^ this->Get(2, 3) ^ o.Get(3, 0);
+    m.Get(2, 1) = this->Get(2, 0) ^ o.Get(0, 1) ^ this->Get(2, 1) ^ o.Get(1, 1) ^ this->Get(2, 2) ^ o.Get(2, 1) ^ this->Get(2, 3) ^ o.Get(3, 1);
+    m.Get(2, 2) = this->Get(2, 0) ^ o.Get(0, 2) ^ this->Get(2, 1) ^ o.Get(1, 2) ^ this->Get(2, 2) ^ o.Get(2, 2) ^ this->Get(2, 3) ^ o.Get(3, 2);
+    m.Get(2, 3) = this->Get(2, 0) ^ o.Get(0, 3) ^ this->Get(2, 1) ^ o.Get(1, 3) ^ this->Get(2, 2) ^ o.Get(2, 3) ^ this->Get(2, 3) ^ o.Get(3, 3);
+
+    m.Get(3, 0) = this->Get(3, 0) ^ o.Get(0, 0) ^ this->Get(3, 1) ^ o.Get(1, 0) ^ this->Get(3, 2) ^ o.Get(2, 0) ^ this->Get(3, 3) ^ o.Get(3, 0);
+    m.Get(3, 1) = this->Get(3, 0) ^ o.Get(0, 1) ^ this->Get(3, 1) ^ o.Get(1, 1) ^ this->Get(3, 2) ^ o.Get(2, 1) ^ this->Get(3, 3) ^ o.Get(3, 1);
+    m.Get(3, 2) = this->Get(3, 0) ^ o.Get(0, 2) ^ this->Get(3, 1) ^ o.Get(1, 2) ^ this->Get(3, 2) ^ o.Get(2, 2) ^ this->Get(3, 3) ^ o.Get(3, 2);
+    m.Get(3, 3) = this->Get(3, 0) ^ o.Get(0, 3) ^ this->Get(3, 1) ^ o.Get(1, 3) ^ this->Get(3, 2) ^ o.Get(2, 3) ^ this->Get(3, 3) ^ o.Get(3, 3);
+
+    return m;
+  }
+
+  const std::uint32_t& BlockMatrix::Get(const std::uint8_t row, const std::uint8_t column) const {
+    return data[column*4 + row];
+  }
+
+  std::uint32_t& BlockMatrix::Get(const std::uint8_t row, const std::uint8_t column){
+    return data[column*4 + row];
+  }
+
+  bool BlockMatrix::operator==(const BlockMatrix& other) const {
+    return data == other.data;
+  }
+
+  bool BlockMatrix::operator!=(const BlockMatrix& other) const {
+    return data != other.data;
+  }
+}
+
diff --git a/GCryptLib/src/Feistel.cpp b/GCryptLib/src/Feistel.cpp
index 9ac75da..31d916d 100644
--- a/GCryptLib/src/Feistel.cpp
+++ b/GCryptLib/src/Feistel.cpp
@@ -1,6 +1,7 @@
 #include <unordered_map>
 #include "GCrypt/Feistel.h"
 #include "GCrypt/Util.h"
+#include "GCrypt/BlockMatrix.h"
 #include "GCrypt/Config.h"
 
 namespace Leonetienne::GCrypt {
@@ -69,8 +70,8 @@ namespace Leonetienne::GCrypt {
     // Shift to left by 1
     m_expanded = Shiftl(m_expanded, 1);
 
-    // Xor with key
-    m_expanded ^= key;
+    // Matrix-mult with key
+    m_expanded = (BlockMatrix(m_expanded) * BlockMatrix(key)).ToBlock();
 
     // Non-linearly apply subsitution boxes
     std::stringstream ss;