diff --git a/dnet-ariadneplus-graphdb-publisher/src/main/java/eu/dnetlib/ariadneplus/elasticsearch/BulkUpload.java b/dnet-ariadneplus-graphdb-publisher/src/main/java/eu/dnetlib/ariadneplus/elasticsearch/BulkUpload.java
index 0446ea7..eedcbc6 100644
--- a/dnet-ariadneplus-graphdb-publisher/src/main/java/eu/dnetlib/ariadneplus/elasticsearch/BulkUpload.java
+++ b/dnet-ariadneplus-graphdb-publisher/src/main/java/eu/dnetlib/ariadneplus/elasticsearch/BulkUpload.java
@@ -4,6 +4,8 @@ import eu.dnetlib.ariadneplus.elasticsearch.model.AriadnePlusEntry;
 import eu.dnetlib.ariadneplus.elasticsearch.model.AriadneResource;
 import eu.dnetlib.ariadneplus.elasticsearch.model.Spatial;
 import eu.dnetlib.ariadneplus.reader.ResourceManager;
+import eu.dnetlib.ariadneplus.reader.utils.ESUtils;
+import org.apache.commons.codec.digest.DigestUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -28,7 +30,10 @@ import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 
 import javax.annotation.PostConstruct;
+import javax.xml.bind.DatatypeConverter;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -188,12 +193,13 @@ public class BulkUpload {
                     ace.getSpatial().clear();
                     ace.setSpatial(dedupSpatials);
                 }
-
-                String[] splits = ace.getIdentifier().split("/");
-
                 log.debug("JSON >>>> "+ace.toJson());
 
-                String idES = splits[splits.length-1];
+                MessageDigest digest = MessageDigest.getInstance("SHA-256");
+                byte[] encodedhash = digest.digest(
+                        ace.getIdentifier().getBytes(StandardCharsets.UTF_8));
+                String idES = ESUtils.bytesToHex(encodedhash);
+                log.debug("indexing " + ace.getIdentifier() + " > " + idES);
                 request.add(new IndexRequest(elasticSearchIndexName).id(idES)
                         .source(ace.toJson(),XContentType.JSON));
                 long start = System.currentTimeMillis();
diff --git a/dnet-ariadneplus-graphdb-publisher/src/main/java/eu/dnetlib/ariadneplus/reader/utils/ESUtils.java b/dnet-ariadneplus-graphdb-publisher/src/main/java/eu/dnetlib/ariadneplus/reader/utils/ESUtils.java
index 60bd239..9c703ad 100644
--- a/dnet-ariadneplus-graphdb-publisher/src/main/java/eu/dnetlib/ariadneplus/reader/utils/ESUtils.java
+++ b/dnet-ariadneplus-graphdb-publisher/src/main/java/eu/dnetlib/ariadneplus/reader/utils/ESUtils.java
@@ -61,4 +61,16 @@ public class ESUtils {
         ZonedDateTime zd = ZonedDateTime.parse(BSTDate, BST_FORMATTER);
         return zd.format(elasticSearchDateFormatter);
     }
+
+    public static String bytesToHex(byte[] hash) {
+        StringBuilder hexString = new StringBuilder(2 * hash.length);
+        for (int i = 0; i < hash.length; i++) {
+            String hex = Integer.toHexString(0xff & hash[i]);
+            if(hex.length() == 1) {
+                hexString.append('0');
+            }
+            hexString.append(hex);
+        }
+        return hexString.toString();
+    }
 }