diff --git a/src/espstrutils.cpp b/src/espstrutils.cpp
index 0b96dd9..684689a 100644
--- a/src/espstrutils.cpp
+++ b/src/espstrutils.cpp
@@ -4,7 +4,6 @@
 #define LOG_LOCAL_LEVEL CONFIG_ESPCPPUTILS_LOG_LOCAL_LEVEL
 
 // system includes
-#include <assert.h>
 #include <utility>
 
 // esp-idf includes
@@ -18,10 +17,6 @@ using namespace std::string_literals;
 namespace espcpputils {
 namespace {
 constexpr const char * const TAG = "ESPCPPUTILS";
-
-tl::expected<char *, std::string> sodium_bin2hex(char * const hex, const size_t hex_maxlen,
-                     const unsigned char * const bin, const size_t bin_len)
-    __attribute__ ((nonnull(1)));
 } // namespace
 
 std::string toString(sntp_sync_mode_t val)
@@ -86,97 +81,4 @@ std::string toString(esp_reset_reason_t val)
     }
 }
 
-std::string toHexString(std::basic_string_view<unsigned char> buf)
-{
-    std::string hex(buf.size() * 2 + 1, {});
-    assert(hex.size() == buf.size() * 2 + 1);
-
-    if (const auto result = sodium_bin2hex(hex.data(), hex.size(), buf.data(), buf.size()); !result)
-    {
-        auto msg = fmt::format("sodium_bin2hex() failed with {}", result.error());
-        ESP_LOGW(TAG, "%.*s", msg.size(), msg.data());
-        return {};
-    }
-
-    hex.resize(hex.size() - 1);
-    assert(hex.size() == buf.size() * 2);
-
-    return hex;
-}
-
-tl::expected<std::basic_string<unsigned char>, std::string> fromHexString(std::string_view hex)
-{
-    if (hex.size() % 2 != 0)
-        return tl::make_unexpected("hex length not even");
-
-    std::basic_string<unsigned char> result;
-    result.reserve(hex.size() / 2);
-
-    for (auto iter = std::cbegin(hex); iter != std::cend(hex); )
-    {
-        union {
-            unsigned char c;
-            struct {
-                unsigned char nibble1:4;
-                unsigned char nibble0:4;
-            } nibbles;
-        };
-
-        switch (const auto c = *iter)
-        {
-        case '0'...'9': nibbles.nibble0 = c - '0'; break;
-        case 'A'...'F': nibbles.nibble0 = c - 'A' + 10; break;
-        case 'a'...'f': nibbles.nibble0 = c - 'a' + 10; break;
-        default:
-            return tl::make_unexpected(fmt::format("invalid character {} at pos {}", c, std::distance(std::begin(hex), iter)));
-        }
-
-        iter++;
-
-        switch (const auto c = *iter)
-        {
-        case '0'...'9': nibbles.nibble1 = c - '0'; break;
-        case 'A'...'F': nibbles.nibble1 = c - 'A' + 10; break;
-        case 'a'...'f': nibbles.nibble1 = c - 'a' + 10; break;
-        default:
-            return tl::make_unexpected(fmt::format("invalid character {} at pos {}", c, std::distance(std::begin(hex), iter)));
-        }
-
-        iter++;
-
-        result.push_back(c);
-    }
-
-    return result;
-}
-
-namespace {
-/* Derived from original code by CodesInChaos */
-tl::expected<char *, std::string>
-sodium_bin2hex(char *const hex, const size_t hex_maxlen,
-               const unsigned char *const bin, const size_t bin_len)
-{
-    size_t       i = (size_t) 0U;
-    unsigned int x;
-    int          b;
-    int          c;
-
-    if (bin_len >= SIZE_MAX / 2 || hex_maxlen <= bin_len * 2U) {
-        return tl::make_unexpected("misuse because bin_len >= SIZE_MAX / 2 || hex_maxlen <= bin_len * 2U");
-    }
-    while (i < bin_len) {
-        c = bin[i] & 0xf;
-        b = bin[i] >> 4;
-        x = (unsigned char) (87U + c + (((c - 10U) >> 8) & ~38U)) << 8 |
-            (unsigned char) (87U + b + (((b - 10U) >> 8) & ~38U));
-        hex[i * 2U] = (char) x;
-        x >>= 8;
-        hex[i * 2U + 1U] = (char) x;
-        i++;
-    }
-    hex[i * 2U] = 0U;
-
-    return hex;
-}
-} // namespace
 } // namespace espcpputils
diff --git a/src/espstrutils.h b/src/espstrutils.h
index babd6e6..576aee5 100644
--- a/src/espstrutils.h
+++ b/src/espstrutils.h
@@ -2,10 +2,6 @@
 
 // system includes
 #include <string>
-#include <string_view>
-
-// 3rdparty lib includes
-#include <tl/expected.hpp>
 
 // esp-idf includes
 #include <esp_sntp.h>
@@ -18,12 +14,4 @@ std::string toString(sntp_sync_status_t val);
 std::string toString(esp_log_level_t val);
 std::string toString(esp_reset_reason_t val);
 
-std::string toHexString(std::basic_string_view<unsigned char> buf);
-inline std::string toHexString(std::string_view str)
-{
-    return toHexString(std::basic_string_view<unsigned char>{reinterpret_cast<const unsigned char *>(str.data()), str.size()});
-}
-
-tl::expected<std::basic_string<unsigned char>, std::string> fromHexString(std::string_view hex);
-
 } // namespace espcpputils