diff --git a/library/lms.c b/library/lms.c
index 00525bb..08fe753 100644
--- a/library/lms.c
+++ b/library/lms.c
@@ -112,7 +112,7 @@
         goto exit;
     }
 
-    mbedtls_lms_unsigned_int_to_network_bytes(r_node_idx, 4, r_node_idx_bytes);
+    MBEDTLS_PUT_UINT32_BE(r_node_idx, r_node_idx_bytes, 0);
     status = psa_hash_update(&op, r_node_idx_bytes, 4);
     if (status != PSA_SUCCESS) {
         goto exit;
@@ -186,7 +186,7 @@
         goto exit;
     }
 
-    mbedtls_lms_unsigned_int_to_network_bytes(r_node_idx, 4, r_node_idx_bytes);
+    MBEDTLS_PUT_UINT32_BE(r_node_idx, r_node_idx_bytes, 0);
     status = psa_hash_update(&op, r_node_idx_bytes, 4);
     if (status != PSA_SUCCESS) {
         goto exit;
@@ -237,10 +237,7 @@
     mbedtls_lms_algorithm_type_t type;
     mbedtls_lmots_algorithm_type_t otstype;
 
-    type = (mbedtls_lms_algorithm_type_t) mbedtls_lms_network_bytes_to_unsigned_int(
-        MBEDTLS_LMS_TYPE_LEN,
-        key +
-        PUBLIC_KEY_TYPE_OFFSET);
+    type = (mbedtls_lms_algorithm_type_t) MBEDTLS_GET_UINT32_BE(key, PUBLIC_KEY_TYPE_OFFSET);
     if (type != MBEDTLS_LMS_SHA256_M32_H10) {
         return MBEDTLS_ERR_LMS_BAD_INPUT_DATA;
     }
@@ -250,10 +247,8 @@
         return MBEDTLS_ERR_LMS_BAD_INPUT_DATA;
     }
 
-    otstype = (mbedtls_lmots_algorithm_type_t) mbedtls_lms_network_bytes_to_unsigned_int(
-        MBEDTLS_LMOTS_TYPE_LEN,
-        key +
-        PUBLIC_KEY_OTSTYPE_OFFSET);
+    otstype = (mbedtls_lmots_algorithm_type_t)
+              MBEDTLS_GET_UINT32_BE(key, PUBLIC_KEY_OTSTYPE_OFFSET);
     if (otstype != MBEDTLS_LMOTS_SHA256_N32_W8) {
         return MBEDTLS_ERR_LMS_BAD_INPUT_DATA;
     }
@@ -282,12 +277,8 @@
         return MBEDTLS_ERR_LMS_BAD_INPUT_DATA;
     }
 
-    mbedtls_lms_unsigned_int_to_network_bytes(
-        ctx->params.type,
-        MBEDTLS_LMS_TYPE_LEN, key + PUBLIC_KEY_TYPE_OFFSET);
-    mbedtls_lms_unsigned_int_to_network_bytes(ctx->params.otstype,
-                                              MBEDTLS_LMOTS_TYPE_LEN,
-                                              key + PUBLIC_KEY_OTSTYPE_OFFSET);
+    MBEDTLS_PUT_UINT32_BE(ctx->params.type, key, PUBLIC_KEY_TYPE_OFFSET);
+    MBEDTLS_PUT_UINT32_BE(ctx->params.otstype, key, PUBLIC_KEY_OTSTYPE_OFFSET);
     memcpy(key + PUBLIC_KEY_I_KEY_ID_OFFSET,
            ctx->params.I_key_identifier,
            MBEDTLS_LMOTS_I_KEY_ID_LEN);
@@ -339,9 +330,7 @@
         return MBEDTLS_ERR_LMS_VERIFY_FAILED;
     }
 
-    if (mbedtls_lms_network_bytes_to_unsigned_int(MBEDTLS_LMOTS_TYPE_LEN,
-                                                  sig + SIG_OTS_SIG_OFFSET +
-                                                  MBEDTLS_LMOTS_SIG_TYPE_OFFSET)
+    if (MBEDTLS_GET_UINT32_BE(sig, SIG_OTS_SIG_OFFSET + MBEDTLS_LMOTS_SIG_TYPE_OFFSET)
         != MBEDTLS_LMOTS_SHA256_N32_W8) {
         return MBEDTLS_ERR_LMS_VERIFY_FAILED;
     }
@@ -350,15 +339,13 @@
         return MBEDTLS_ERR_LMS_VERIFY_FAILED;
     }
 
-    if (mbedtls_lms_network_bytes_to_unsigned_int(MBEDTLS_LMS_TYPE_LEN,
-                                                  sig + SIG_TYPE_OFFSET(ctx->params.otstype))
+    if (MBEDTLS_GET_UINT32_BE(sig, SIG_TYPE_OFFSET(ctx->params.otstype))
         != MBEDTLS_LMS_SHA256_M32_H10) {
         return MBEDTLS_ERR_LMS_VERIFY_FAILED;
     }
 
 
-    q_leaf_identifier = mbedtls_lms_network_bytes_to_unsigned_int(
-        MBEDTLS_LMOTS_Q_LEAF_ID_LEN, sig + SIG_Q_LEAF_ID_OFFSET);
+    q_leaf_identifier = MBEDTLS_GET_UINT32_BE(sig, SIG_Q_LEAF_ID_OFFSET);
 
     if (q_leaf_identifier >= MERKLE_TREE_LEAF_NODE_AM(ctx->params.type)) {
         return MBEDTLS_ERR_LMS_VERIFY_FAILED;
@@ -367,9 +354,7 @@
     memcpy(ots_params.I_key_identifier,
            ctx->params.I_key_identifier,
            MBEDTLS_LMOTS_I_KEY_ID_LEN);
-    mbedtls_lms_unsigned_int_to_network_bytes(q_leaf_identifier,
-                                              MBEDTLS_LMOTS_Q_LEAF_ID_LEN,
-                                              ots_params.q_leaf_identifier);
+    MBEDTLS_PUT_UINT32_BE(q_leaf_identifier, ots_params.q_leaf_identifier, 0);
     ots_params.type = ctx->params.otstype;
 
     ret = mbedtls_lmots_calculate_public_key_candidate(&ots_params,
@@ -753,12 +738,8 @@
         return ret;
     }
 
-    mbedtls_lms_unsigned_int_to_network_bytes(ctx->params.type,
-                                              MBEDTLS_LMS_TYPE_LEN,
-                                              sig + SIG_TYPE_OFFSET(ctx->params.otstype));
-    mbedtls_lms_unsigned_int_to_network_bytes(q_leaf_identifier,
-                                              MBEDTLS_LMOTS_Q_LEAF_ID_LEN,
-                                              sig + SIG_Q_LEAF_ID_OFFSET);
+    MBEDTLS_PUT_UINT32_BE(ctx->params.type, sig, SIG_TYPE_OFFSET(ctx->params.otstype));
+    MBEDTLS_PUT_UINT32_BE(q_leaf_identifier, sig, SIG_Q_LEAF_ID_OFFSET);
 
     ret = get_merkle_path(ctx,
                           MERKLE_TREE_INTERNAL_NODE_AM(ctx->params.type) + q_leaf_identifier,