diff --git a/tf_fuzz/lib/tfm_boilerplate.txt b/tf_fuzz/lib/tfm_boilerplate.txt
index 3634238..5b65684 100644
--- a/tf_fuzz/lib/tfm_boilerplate.txt
+++ b/tf_fuzz/lib/tfm_boilerplate.txt
@@ -169,7 +169,7 @@
     }
     /* Check that the data is correct */
     if (memcmp($act_data, $exp_data,
-                   $length) != 0) {
+                   $length) != $check_expect) {
         TEST_FAIL("Read data should be equal to result data");
         return;
     }
diff --git a/tf_fuzz/tfz-cpp/calls/psa_call.cpp b/tf_fuzz/tfz-cpp/calls/psa_call.cpp
index 46af409..0e1680b 100644
--- a/tf_fuzz/tfz-cpp/calls/psa_call.cpp
+++ b/tf_fuzz/tfz-cpp/calls/psa_call.cpp
@@ -88,51 +88,104 @@
 {
     string formalized;  // "proper" result string
 
-    if (!exp_data.pf_nothing) {
-        if (exp_data.pf_pass) {
-            find_replace_all ("$expect",
-                              test_state->bplate->bplate_string[sst_pass_string],
-                              check_code);
-        } else if (exp_data.pf_fail) {
-            // Check for not-success:
-            find_replace_1st ("!=", "==",
-                              check_code);
-            find_replace_all ("$expect",
-                              test_state->bplate->bplate_string[sst_pass_string],
-                              check_code);
-            find_replace_1st ("expected ", "expected not ",
-                              check_code);
+    if (exp_data.pf_nothing) { // do not generate result checks
+        return;
+
+    }
+    if (exp_data.pf_pass) { // expect pass
+        find_replace_all ("$expect",
+                          test_state->bplate->bplate_string[sst_pass_string],
+                          check_code);
+
+        // `check "foo"`
+        find_replace_all ("$check_expect",
+                          "0",
+                          check_code);
+
+    } else if (exp_data.pf_fail) { // expect fail
+
+      // If the command is `... check "foo" expect fail;`, the fail
+      // binds to the check, not the command itself.
+      if (exp_data.data_specified) {
+        // expect a pass for the sst call itself.
+        find_replace_all ("$expect",
+                          test_state->bplate->bplate_string[sst_pass_string],
+                          check_code);
+
+        // expect a failure for the check.
+        find_replace_all ("!= $check_expect",
+                          "== 0",
+                          check_code);
+
+        find_replace_1st ("should be equal", "should not be equal",
+                          check_code);
         } else {
-            if (exp_data.pf_specified) {
-                formalized = formalize (exp_data.pf_result_string, "PSA_ERROR_");
-                find_replace_all ("$expect", formalized, check_code);
-            } else {
-                // Figure out what the message should read:
-                switch (asset_info.how_asset_found) {
-                    case asset_search::found_active:
-                    case asset_search::created_new:
-                        find_replace_all ("$expect",
-                                          test_state->bplate->
-                                              bplate_string[sst_pass_string],
-                                          check_code);
-                        break;
-                    case asset_search::found_deleted:
-                    case asset_search::not_found:
-                        find_replace_all ("$expect",
-                                          test_state->bplate->
-                                              bplate_string[sst_fail_removed],
-                                          check_code);
-                        break;
-                    default:
-                        find_replace_1st ("!=", "==",
-                                          check_code);  // like "fail", just make sure...
-                        find_replace_all ("$expect",
-                                          test_state->bplate->
-                                              bplate_string[sst_pass_string],
-                                          check_code);  // ... it's *not* PSA_SUCCESS
-                        break;
-                }
-            }
+        // Check for not-success:
+        find_replace_1st ("!=", "==",
+                          check_code);
+        find_replace_all ("$expect",
+                          test_state->bplate->bplate_string[sst_pass_string],
+                          check_code);
+        find_replace_1st ("expected ", "expected not ",
+                          check_code);
+        }
+    }
+
+    else if (exp_data.pf_specified) { // expect <PSA_ERROR_CODE>
+        formalized = formalize (exp_data.pf_result_string, "PSA_ERROR_");
+        find_replace_all ("$expect", formalized, check_code);
+
+        // NOTE: Assumes that the variable used to store the actual
+        // value initialised to a different value than the expected
+        // value.
+        find_replace_all ("!= $check_expect","== 0",check_code);
+        find_replace_1st ("should be equal", "should not be equal",
+                          check_code);
+    }
+
+    else { // no explicit expect -- simulate
+
+        // Figure out what the message should read:
+        switch (asset_info.how_asset_found) {
+            case asset_search::found_active:
+            case asset_search::created_new:
+                find_replace_all ("$expect",
+                                  test_state->bplate->
+                                      bplate_string[sst_pass_string],
+                                  check_code);
+
+                find_replace_all ("$check_expect","0",check_code);
+                break;
+            case asset_search::found_deleted:
+            case asset_search::not_found:
+                find_replace_all ("$expect",
+                                  test_state->bplate->
+                                      bplate_string[sst_fail_removed],
+                                  check_code);
+
+                // NOTE: Assumes that the variable used to store the actual
+                // value initialised to a different value than the expected
+                // value.
+                find_replace_all ("!= $check_expect","== 0",check_code);
+                find_replace_1st ("should be equal", "should not be equal",
+                                  check_code);
+                break;
+            default:
+                find_replace_1st ("!=", "==",
+                                  check_code);  // like "fail", just make sure...
+
+                find_replace_all ("$expect",
+                                  test_state->bplate->
+                                      bplate_string[sst_pass_string],
+                                  check_code);  // ... it's *not* PSA_SUCCESS
+
+                // NOTE: Assumes that the variable used to store the actual
+                // value initialised to a different value than the expected
+                // value.
+                find_replace_all ("!= $check_expect","== 0",check_code);
+                find_replace_1st ("should be equal", "should not be equal",
+                                  check_code);
+                break;
         }
     }
 }
diff --git a/tf_fuzz/tfz-cpp/regression/000008_set_sst_name_rand_data_read_check_wrong/exp_test.c b/tf_fuzz/tfz-cpp/regression/000008_set_sst_name_rand_data_read_check_wrong/exp_test.c
index 400ac89..974b2ca 100644
--- a/tf_fuzz/tfz-cpp/regression/000008_set_sst_name_rand_data_read_check_wrong/exp_test.c
+++ b/tf_fuzz/tfz-cpp/regression/000008_set_sst_name_rand_data_read_check_wrong/exp_test.c
@@ -49,14 +49,14 @@
     }
     sst_status = psa_ps_get\(@@@001@@@, 0, @@@003@@@, snortwaggle_act_data
                             &snortwaggle_act_length);
-    if (sst_status == PSA_SUCCESS) {
-        TEST_FAIL("psa_ps_get() expected not PSA_SUCCESS.");
+    if (sst_status != PSA_SUCCESS) {
+        TEST_FAIL("psa_ps_get() expected PSA_SUCCESS.");
         return;
     }
     /* Check that the data is correct */
     if \(memcmp\(snortwaggle_act_data, snortwaggle_exp_data,
-                   snortwaggle_act_length\) != 0\) {
-        TEST_FAIL("Read data should be equal to result data");
+                   snortwaggle_act_length\) == 0\) {
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
 
diff --git a/tf_fuzz/tfz-cpp/regression/000010_read_nonexistent_sst_check_string/exp_test.c b/tf_fuzz/tfz-cpp/regression/000010_read_nonexistent_sst_check_string/exp_test.c
index 72085dc..0cd77b8 100644
--- a/tf_fuzz/tfz-cpp/regression/000010_read_nonexistent_sst_check_string/exp_test.c
+++ b/tf_fuzz/tfz-cpp/regression/000010_read_nonexistent_sst_check_string/exp_test.c
@@ -46,8 +46,8 @@
     }
     /* Check that the data is correct */
     if \(memcmp\(napoleon_act_data, napoleon_exp_data,
-                   napoleon_act_length\) != 0\) {
-        TEST_FAIL("Read data should be equal to result data");
+                   napoleon_act_length\) == 0\) {
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
 
diff --git a/tf_fuzz/tfz-cpp/regression/000012_read_nonexistent_sst_check_string_expect_other/exp_test.c b/tf_fuzz/tfz-cpp/regression/000012_read_nonexistent_sst_check_string_expect_other/exp_test.c
index 74c1545..93e16b5 100644
--- a/tf_fuzz/tfz-cpp/regression/000012_read_nonexistent_sst_check_string_expect_other/exp_test.c
+++ b/tf_fuzz/tfz-cpp/regression/000012_read_nonexistent_sst_check_string_expect_other/exp_test.c
@@ -46,8 +46,8 @@
     }
     /* Check that the data is correct */
     if \(memcmp\(napoleon_act_data, napoleon_exp_data,
-                   napoleon_act_length\) != 0\) \{
-        TEST_FAIL("Read data should be equal to result data");
+                   napoleon_act_length\) == 0\) \{
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
 
diff --git a/tf_fuzz/tfz-cpp/regression/000017_read_sst_check_single_asset_multiple_times/exp_test.c b/tf_fuzz/tfz-cpp/regression/000017_read_sst_check_single_asset_multiple_times/exp_test.c
index 1abe615..a251a42 100644
--- a/tf_fuzz/tfz-cpp/regression/000017_read_sst_check_single_asset_multiple_times/exp_test.c
+++ b/tf_fuzz/tfz-cpp/regression/000017_read_sst_check_single_asset_multiple_times/exp_test.c
@@ -51,38 +51,38 @@
     }
     sst_status = psa_ps_get\(@@@001@@@, 0, \d+, just_checking_act_data,
                             &just_checking_act_length);
-    if (sst_status == PSA_SUCCESS) {
-        TEST_FAIL("psa_ps_get() expected not PSA_SUCCESS.");
+    if (sst_status != PSA_SUCCESS) {
+        TEST_FAIL("psa_ps_get() expected PSA_SUCCESS.");
         return;
     }
     /* Check that the data is correct */
     if \(memcmp\(just_checking_act_data, just_checking_exp_data,
-                   just_checking_act_length\) != 0\) {
-        TEST_FAIL("Read data should be equal to result data");
+                   just_checking_act_length\) == 0\) {
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
     sst_status = psa_ps_get\(@@@001@@@, 0, \d+, just_checking_act_data,
                             &just_checking_act_length);
-    if (sst_status == PSA_SUCCESS) {
-        TEST_FAIL("psa_ps_get() expected not PSA_SUCCESS.");
+    if (sst_status != PSA_SUCCESS) {
+        TEST_FAIL("psa_ps_get() expected PSA_SUCCESS.");
         return;
     }
     /* Check that the data is correct */
     if \(memcmp\(just_checking_act_data, just_checking_exp_data_1,
-                   just_checking_act_length\) != 0\) {
-        TEST_FAIL("Read data should be equal to result data");
+                   just_checking_act_length\) == 0\) {
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
     sst_status = psa_ps_get\(@@@001@@@, 0, \d+, just_checking_act_data,
                             &just_checking_act_length);
-    if (sst_status == PSA_SUCCESS) {
-        TEST_FAIL("psa_ps_get() expected not PSA_SUCCESS.");
+    if (sst_status != PSA_SUCCESS) {
+        TEST_FAIL("psa_ps_get() expected PSA_SUCCESS.");
         return;
     }
     /* Check that the data is correct */
     if \(memcmp\(just_checking_act_data, just_checking_exp_data_2,
-                   just_checking_act_length\) != 0\) {
-        TEST_FAIL("Read data should be equal to result data");
+                   just_checking_act_length\) == 0\) {
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
     sst_status = psa_ps_get\(@@@001@@@, 0, \d+, just_checking_act_data,
diff --git a/tf_fuzz/tfz-cpp/regression/000018_000016_and_000017/exp_test.c b/tf_fuzz/tfz-cpp/regression/000018_000016_and_000017/exp_test.c
index 353f3fb..06b82b4 100644
--- a/tf_fuzz/tfz-cpp/regression/000018_000016_and_000017/exp_test.c
+++ b/tf_fuzz/tfz-cpp/regression/000018_000016_and_000017/exp_test.c
@@ -61,14 +61,14 @@
     }
     sst_status = psa_ps_get\(@@@001@@@, 0, 11, indecisive_act_data,
                             &indecisive_act_length);
-    if (sst_status == PSA_SUCCESS) {
-        TEST_FAIL("psa_ps_get() expected not PSA_SUCCESS.");
+    if (sst_status != PSA_SUCCESS) {
+        TEST_FAIL("psa_ps_get() expected PSA_SUCCESS.");
         return;
     }
     /* Check that the data is correct */
     if (memcmp(indecisive_act_data, indecisive_exp_data,
-                   indecisive_act_length\) != 0\) {
-        TEST_FAIL("Read data should be equal to result data");
+                   indecisive_act_length\) == 0\) {
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
     /* Resetting SST asset "indecisive," with data "Second val...". */
@@ -80,14 +80,14 @@
     }
     sst_status = psa_ps_get\(@@@001@@@, 0, 12, indecisive_act_data,
                             &indecisive_act_length);
-    if (sst_status == PSA_SUCCESS) {
-        TEST_FAIL("psa_ps_get() expected not PSA_SUCCESS.");
+    if (sst_status != PSA_SUCCESS) {
+        TEST_FAIL("psa_ps_get() expected PSA_SUCCESS.");
         return;
     }
     /* Check that the data is correct */
     if (memcmp(indecisive_act_data, indecisive_exp_data_1,
-                   indecisive_act_length) != 0) {
-        TEST_FAIL("Read data should be equal to result data");
+                   indecisive_act_length) == 0) {
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
     /\* Resetting SST asset "indecisive," with data "@@001@10@@...". \*/
@@ -106,14 +106,14 @@
     }
     sst_status = psa_ps_get\(@@@001@@@, 0, 12, indecisive_act_data,
                             &indecisive_act_length);
-    if (sst_status == PSA_SUCCESS) {
-        TEST_FAIL("psa_ps_get() expected not PSA_SUCCESS.");
+    if (sst_status != PSA_SUCCESS) {
+        TEST_FAIL("psa_ps_get() expected PSA_SUCCESS.");
         return;
     }
     /* Check that the data is correct */
     if (memcmp(indecisive_act_data, indecisive_exp_data_2,
-                   indecisive_act_length) != 0) {
-        TEST_FAIL("Read data should be equal to result data");
+                   indecisive_act_length) == 0) {
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
     /\* Resetting SST asset "indecisive," with data "@@002@10@@...". \*/
diff --git a/tf_fuzz/tfz-cpp/regression/000021_abbreviated_result_codes/exp_test.c b/tf_fuzz/tfz-cpp/regression/000021_abbreviated_result_codes/exp_test.c
index 74c1545..93e16b5 100644
--- a/tf_fuzz/tfz-cpp/regression/000021_abbreviated_result_codes/exp_test.c
+++ b/tf_fuzz/tfz-cpp/regression/000021_abbreviated_result_codes/exp_test.c
@@ -46,8 +46,8 @@
     }
     /* Check that the data is correct */
     if \(memcmp\(napoleon_act_data, napoleon_exp_data,
-                   napoleon_act_length\) != 0\) \{
-        TEST_FAIL("Read data should be equal to result data");
+                   napoleon_act_length\) == 0\) \{
+        TEST_FAIL("Read data should not be equal to result data");
         return;
     }
 
diff --git a/tf_fuzz/tfz-cpp/utility/data_blocks.hpp b/tf_fuzz/tfz-cpp/utility/data_blocks.hpp
index bee4594..723ee95 100644
--- a/tf_fuzz/tfz-cpp/utility/data_blocks.hpp
+++ b/tf_fuzz/tfz-cpp/utility/data_blocks.hpp
@@ -43,7 +43,7 @@
         bool pf_nothing;  // true to not generate results-check(s)
         bool pf_pass;  // if !expect.pf_nothing, then pass is expected
         bool pf_fail;  // if "expect fail" was specified
-        bool pf_specified;
+        bool pf_specified; // if "expect <ERROR_CODE>" was specified
             /* if !pf_nothing && !pf_pass, then
                true == expected result was specified
                false == tf_fuzz must model expected result, and
@@ -185,7 +185,7 @@
         bool can_encrypt;  // OK for encryption (fail other uses).
         bool can_decrypt;  // OK for decryption (fail other uses).
         bool can_sign;     // OK for signing (fail other operations).
-        bool can_verify;   // OK for verifing a message signature (fail other uses).
+        bool can_verify;   // OK for verifying a message signature (fail other uses).
         bool derivable;    // OK for derive other keys (fail other uses).
         bool persistent;   // must be deleted at the end of test.
         string usage_string;