--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Core/DicomFormat/DicomInstanceHasher.h	Fri Nov 09 11:13:29 2012 +0100
@@ -0,0 +1,88 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012 Medical Physics Department, CHU of Liege,
+ * Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders of this
+ * program give permission to link the code of its release with the
+ * OpenSSL project's "OpenSSL" library (or with modified versions of it
+ * that use the same license as the "OpenSSL" library), and distribute
+ * the linked executables. You must obey the GNU General Public License
+ * in all respects for all of the code used other than "OpenSSL". If you
+ * modify file(s) with this exception, you may extend this exception to
+ * your version of the file(s), but you are not obligated to do so. If
+ * you do not wish to do so, delete this exception statement from your
+ * version. If you delete this exception statement from all source files
+ * in the program, then also delete it here.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include "DicomMap.h"
+
+namespace Orthanc
+{
+  /**
+   * This class implements the hashing mechanism that is used to
+   * convert DICOM unique identifiers to Orthanc identifiers. Any
+   * Orthanc identifier for a DICOM resource corresponds to the SHA-1
+   * hash of the DICOM identifiers. 
+
+   * \note SHA-1 hash is used because it is less sensitive to
+   * collision attacks than MD5. <a
+   * href="http://en.wikipedia.org/wiki/SHA-256#Comparison_of_SHA_functions">[Reference]</a>
+   **/
+  class DicomInstanceHasher
+  {
+  private:
+    std::string patientId_;
+    std::string instanceUid_;
+    std::string seriesUid_;
+    std::string studyUid_;
+
+  public:
+    DicomInstanceHasher(const DicomMap& instance);
+
+    const std::string& GetPatientId() const
+    {
+      return patientId_;
+    }
+
+    const std::string& GetInstanceUid() const
+    {
+      return instanceUid_;
+    }
+
+    const std::string& GetSeriesUid() const
+    {
+      return seriesUid_;
+    }
+
+    const std::string& GetStudyUid() const
+    {
+      return studyUid_;
+    }
+
+    std::string HashPatient() const;
+
+    std::string HashStudy() const;
+
+    std::string HashSeries() const;
+
+    std::string HashInstance() const;
+  };
+}