diff --git a/cgi-bin/CATS/ApiJudge.pm b/cgi-bin/CATS/ApiJudge.pm
index d3ccb3ac8..6cd098073 100644
--- a/cgi-bin/CATS/ApiJudge.pm
+++ b/cgi-bin/CATS/ApiJudge.pm
@@ -158,6 +158,23 @@ sub insert_req_details {
     print_json({ ok => 1 });
 }
 
+sub get_input_hash {
+    bad_judge and return -1;
+    my ($p) = @_;
+
+    print_json({ hash => CATS::JudgeDB::get_input_hash($p->{problem_id}, $p->{test_rank}) });
+}
+
+sub save_input_hash {
+    bad_judge and return -1;
+    my ($p) = @_;
+
+    CATS::JudgeDB::save_input_hash(
+        $p->{problem_id}, $p->{test_rank}, $p->{hash}});
+
+    print_json({ ok => 1 });
+}
+
 sub save_input_test_data {
     bad_judge and return -1;
     my ($p) = @_;
diff --git a/cgi-bin/CATS/Problem/Storage.pm b/cgi-bin/CATS/Problem/Storage.pm
index bdf2f70b8..fe83039c2 100644
--- a/cgi-bin/CATS/Problem/Storage.pm
+++ b/cgi-bin/CATS/Problem/Storage.pm
@@ -442,8 +442,8 @@ sub insert_problem_content {
     $c = $dbh->prepare(q~
         INSERT INTO tests (
             problem_id, rank, input_validator_id, generator_id, param, std_solution_id, in_file, out_file,
-            points, gen_group
-        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)~
+            points, gen_group, in_file_hash
+        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)~
     );
 
     for (sort { $a->{rank} <=> $b->{rank} } values %{$problem->{tests}}) {
@@ -457,6 +457,7 @@ sub insert_problem_content {
         $c->bind_param(8, $_->{out_file}, { ora_type => 113 });
         $c->bind_param(9, $_->{points});
         $c->bind_param(10, $_->{gen_group});
+        $c->bind_param(11, $_->{hash});
         $c->execute
             or $self->error("Can not add test $_->{rank}: $dbh->errstr");
         $self->note("Test $_->{rank} added");
diff --git a/cgi-bin/CATS/Router.pm b/cgi-bin/CATS/Router.pm
index fe31ee2f1..f6929de38 100644
--- a/cgi-bin/CATS/Router.pm
+++ b/cgi-bin/CATS/Router.pm
@@ -271,6 +271,17 @@ $api_judge_routes = {
     ],
     api_judge_delete_req_details => [ \&CATS::ApiJudge::delete_req_details, req_id => integer, ],
     api_judge_insert_req_details => [ \&CATS::ApiJudge::insert_req_details, params => str, ],
+    api_judge_get_input_hash => [
+        \&CATS::ApiJudge::get_input_hash,
+        problem_id => integer,
+        test_rank => integer,
+    ],
+    api_judge_save_input_hash => [
+        \&CATS::ApiJudge::save_input_hash,
+        problem_id => integer,
+        test_rank => integer,
+        hash => undef,
+    ],
     api_judge_save_input_test_data => [
         \&CATS::ApiJudge::save_input_test_data,
         problem_id => integer,
diff --git a/sql/interbase/init_relations.sql b/sql/interbase/init_relations.sql
index 0573c073c..0d81d53f8 100755
--- a/sql/interbase/init_relations.sql
+++ b/sql/interbase/init_relations.sql
@@ -281,7 +281,8 @@ CREATE TABLE tests (
     out_file        BLOB, /* For generated answer, length = min(out_file_size, save_answer_prefix). */
     out_file_size   INTEGER, /* Size of generated answer, else NULL. */
     points          INTEGER,
-    gen_group       INTEGER
+    gen_group       INTEGER,
+    in_file_hash    VARCHAR(100) DEFAULT NULL
 );
 
 CREATE TABLE testsets (
diff --git a/sql/interbase/migrations/20180226-tests-hash.sql b/sql/interbase/migrations/20180226-tests-hash.sql
new file mode 100644
index 000000000..3d4a6b656
--- /dev/null
+++ b/sql/interbase/migrations/20180226-tests-hash.sql
@@ -0,0 +1,2 @@
+ALTER TABLE tests
+    ADD in_file_hash VARCHAR(100) DEFAULT NULL;