oram

oram.cpp

+/***************************
+ * *************************
+ * Installations: apt-get install libssl-dev
+ * Compile like: g++ oram.cpp -o oram -I/usr/include -L/usr/lib -lssl -lcrypto
+*/
+
+#include <iostream>
+#include <vector>
+#include <openssl/rand.h>
+#include <openssl/evp.h>
+
+#define BLOCK_SIZE 16  // Memory block size
+#define TREE_HEIGHT 4  // Path ORAM tree depth
+
+using namespace std;
+
+// Encrypt data using AES
+void encrypt_block(vector<unsigned char>& data, const unsigned char* key) {
+    EVP_CIPHER_CTX* ctx = EVP_CIPHER_CTX_new();
+
+    unsigned char iv[BLOCK_SIZE] = {0};  // Initialization vector
+
+    EVP_EncryptInit_ex(ctx, EVP_aes_128_cbc(), NULL, key, iv);
+    int len;
+    EVP_EncryptUpdate(ctx, data.data(), &len, data.data(), BLOCK_SIZE);
+    EVP_EncryptFinal_ex(ctx, data.data() + len, &len);
+    EVP_CIPHER_CTX_free(ctx);
+}
+
+// ORAM Storage Class
+class PathORAM {
+private:
+    vector<vector<unsigned char>> storage;  // Encrypted memory blocks
+    unsigned char key[16];                  // AES encryption key
+
+public:
+    PathORAM(int num_blocks) {
+        RAND_bytes(key, sizeof(key));  // Generate encryption key
+        storage.resize(num_blocks, vector<unsigned char>(BLOCK_SIZE, 0));
+    }
+
+    void write(int index, vector<unsigned char> data) {
+        encrypt_block(data, key);
+        storage[index] = data;
+    }
+
+    vector<unsigned char> read(int index) {
+        return storage[index];  // Return encrypted data (decryption step needed)
+    }
+};
+
+int main() {
+    PathORAM oram(16);  // Initialize ORAM with 16 memory blocks
+
+    vector<unsigned char> model_data(BLOCK_SIZE, 42);  // Sample ML model data
+    oram.write(0, model_data);  // Store encrypted model parameters
+
+    vector<unsigned char> retrieved_data = oram.read(0);  // Retrieve encrypted data
+
+    cout << "Encrypted data stored in ORAM: ";
+    for (unsigned char c : retrieved_data) {
+        cout << hex << (int)c << " ";
+    }
+    cout << endl;
+
+    return 0;
+}