diff --git a/src/std_utils.cc b/src/std_utils.cc
index 1ddb2f7..e042ff3 100644
--- a/src/std_utils.cc
+++ b/src/std_utils.cc
@@ -343,5 +343,39 @@ namespace pEp {
             return ret.str();
         }
 
+        std::string bin2hex(const std::vector<unsigned char> &bin)
+        {
+            std::string ret{};
+            std::stringstream ss{};
+            for (const auto &i : bin) {
+                ss << std::hex << std::setfill('0') << std::setw(2) << (int)i;
+            }
+            ret = ss.str();
+            return ret;
+        }
+
+        std::vector<unsigned char> hex2bin(const std::string &hex_str)
+        {
+            std::vector<unsigned char> ret{};
+            if ((hex_str.size() % 2) != 0) {
+                throw std::runtime_error("hex2bin: Invalid hex string: must be even length");
+            }
+            for (int i = 0; i < hex_str.size(); i += 2) {
+                std::ostringstream val_hex{};
+                val_hex << hex_str.at(i);
+                val_hex << hex_str.at(i + 1);
+
+                int val_int;
+                std::istringstream conv_ss{ val_hex.str() };
+                conv_ss >> std::hex >> val_int;
+                if (conv_ss.fail()) {
+                    throw std::runtime_error("hex2bin: invalid hex string" + hex_str);
+                }
+                ret.push_back((unsigned char)val_int);
+            }
+            return ret;
+        }
+
+
     } // namespace Utils
 } // namespace pEp
diff --git a/src/std_utils.hh b/src/std_utils.hh
index 6a2b0eb..84709be 100644
--- a/src/std_utils.hh
+++ b/src/std_utils.hh
@@ -94,6 +94,9 @@ namespace pEp {
         unsigned char random_char(unsigned char min, unsigned char max);
         std::string random_string(unsigned char min, unsigned char max, int len);
 
+        // conversion
+        std::vector<unsigned char> hex2bin(const std::string &hex_str);
+        std::string bin2hex(const std::vector<unsigned char>& bin);
     } // namespace Utils
 } // namespace pEp