diff --git a/key.cpp b/key.cpp
index 0ae24b8..2da3b8d 100644
--- a/key.cpp
+++ b/key.cpp
@@ -261,9 +261,8 @@ bool		Key_file::load_from_file (const char* key_file_name)
 
 bool		Key_file::store_to_file (const char* key_file_name) const
 {
-	mode_t		old_umask = util_umask(0077); // make sure key file is protected
+	create_protected_file(key_file_name);
 	std::ofstream	key_file_out(key_file_name, std::fstream::binary);
-	util_umask(old_umask);
 	if (!key_file_out) {
 		return false;
 	}
diff --git a/util-unix.cpp b/util-unix.cpp
index 2385566..2bdf364 100644
--- a/util-unix.cpp
+++ b/util-unix.cpp
@@ -37,6 +37,7 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <limits.h>
+#include <fcntl.h>
 #include <stdlib.h>
 #include <dirent.h>
 #include <vector>
@@ -72,14 +73,14 @@ void	temp_fstream::open (std::ios_base::openmode mode)
 	char*			path = &path_buffer[0];
 	std::strcpy(path, tmpdir);
 	std::strcpy(path + tmpdir_len, "/git-crypt.XXXXXX");
-	mode_t			old_umask = util_umask(0077);
+	mode_t			old_umask = umask(0077);
 	int			fd = mkstemp(path);
 	if (fd == -1) {
 		int		mkstemp_errno = errno;
-		util_umask(old_umask);
+		umask(old_umask);
 		throw System_error("mkstemp", "", mkstemp_errno);
 	}
-	util_umask(old_umask);
+	umask(old_umask);
 	std::fstream::open(path, mode);
 	if (!std::fstream::is_open()) {
 		unlink(path);
@@ -288,9 +289,13 @@ static void	init_std_streams_platform ()
 {
 }
 
-mode_t util_umask (mode_t mode)
+void	create_protected_file (const char* path)
 {
-	return umask(mode);
+	int	fd = open(path, O_WRONLY | O_CREAT, 0600);
+	if (fd == -1) {
+		throw System_error("open", path, errno);
+	}
+	close(fd);
 }
 
 int util_rename (const char* from, const char* to)
diff --git a/util-win32.cpp b/util-win32.cpp
index 4e6e9c1..4d442db 100644
--- a/util-win32.cpp
+++ b/util-win32.cpp
@@ -346,10 +346,8 @@ static void	init_std_streams_platform ()
 	_setmode(_fileno(stdout), _O_BINARY);
 }
 
-mode_t util_umask (mode_t mode)
+void create_protected_file (const char* path) // TODO
 {
-	// Not available in Windows and function not always defined in Win32 environments
-	return 0;
 }
 
 int util_rename (const char* from, const char* to)
diff --git a/util.hpp b/util.hpp
index 8281294..aa04912 100644
--- a/util.hpp
+++ b/util.hpp
@@ -73,7 +73,7 @@ void		write_be32 (std::ostream& out, uint32_t);
 void*		explicit_memset (void* s, int c, size_t n);	// memset that won't be optimized away
 bool		leakless_equals (const void* a, const void* b, size_t len); // compare bytes w/o leaking timing
 void		init_std_streams ();
-mode_t		util_umask (mode_t);
+void		create_protected_file (const char* path); // create empty file accessible only by current user
 int		util_rename (const char*, const char*);
 std::vector<std::string> get_directory_contents (const char* path);