diff --git a/src/main/java/org/olat/modules/edusharing/EdusharingModule.java b/src/main/java/org/olat/modules/edusharing/EdusharingModule.java
index 13795aa1d9f939b60316de3e48e306cf232a0e4b..06975047d8f0f2362f28fe78fc621a9d271b8e9a 100644
--- a/src/main/java/org/olat/modules/edusharing/EdusharingModule.java
+++ b/src/main/java/org/olat/modules/edusharing/EdusharingModule.java
@@ -82,6 +82,9 @@ public class EdusharingModule extends AbstractSpringModule implements ConfigOnOf
 	private String authAffiliationId;
 	@Value("${edusharing.auth.affiliation.name}")
 	private String authAffiliationName;
+	
+	@Value("${edusharing.user.identifier.key:username}")
+	private String userIdentifierKey;
 
 	@Autowired
 	private EdusharingSecurityService edusharingSignature;
@@ -228,6 +231,10 @@ public class EdusharingModule extends AbstractSpringModule implements ConfigOnOf
 		setStringProperty(EDUSHARING_REPO_PUBLIC_KEY, repoPublicKeyString, true);
 	}
 
+	public String getUserIdentifierKey() {
+		return userIdentifierKey;
+	}
+
 	public String getAuthKeyUseriId() {
 		return authKeyUseriId;
 	}
diff --git a/src/main/java/org/olat/modules/edusharing/GetRenderedParameter.java b/src/main/java/org/olat/modules/edusharing/GetRenderedParameter.java
index d438606b0d3aaaa5762ac94a906d1b9def4e066e..4de68d90fb9927e1289a820356bfc46e89c16cbb 100644
--- a/src/main/java/org/olat/modules/edusharing/GetRenderedParameter.java
+++ b/src/main/java/org/olat/modules/edusharing/GetRenderedParameter.java
@@ -38,7 +38,7 @@ public class GetRenderedParameter {
 	private final String signed;
 	private final String signature;
 	private final String timestamp;
-	private final String encryptedUsername;
+	private final String encryptedUserIdentifier;
 	private final String displayMode;
 	private String width;
 	private String height;
@@ -46,7 +46,7 @@ public class GetRenderedParameter {
 
 	public GetRenderedParameter(String appId, String repoId, String nodeId, String resourceId, String courseId,
 			String version, String locale, String language, String signed, String signature, String timestamp,
-			String encryptedUsername, String displayMode) {
+			String encryptedUserIdentifier, String displayMode) {
 		this.appId = appId;
 		this.repoId = repoId;
 		this.nodeId = nodeId;
@@ -58,7 +58,7 @@ public class GetRenderedParameter {
 		this.signed = signed;
 		this.signature = signature;
 		this.timestamp = timestamp;
-		this.encryptedUsername = encryptedUsername;
+		this.encryptedUserIdentifier = encryptedUserIdentifier;
 		this.displayMode = displayMode;
 	}
 
@@ -106,8 +106,8 @@ public class GetRenderedParameter {
 		return timestamp;
 	}
 
-	public String getEncryptedUsername() {
-		return encryptedUsername;
+	public String getEncryptedUserIdentifier() {
+		return encryptedUserIdentifier;
 	}
 
 	public String getDisplayMode() {
diff --git a/src/main/java/org/olat/modules/edusharing/manager/EdusharingHttpClient.java b/src/main/java/org/olat/modules/edusharing/manager/EdusharingHttpClient.java
index a1ded265558dba043c4eeb0f94b48ed922687999..400d063a78baa1a4a70859eed22b4e33c7bc34bf 100644
--- a/src/main/java/org/olat/modules/edusharing/manager/EdusharingHttpClient.java
+++ b/src/main/java/org/olat/modules/edusharing/manager/EdusharingHttpClient.java
@@ -122,7 +122,7 @@ class EdusharingHttpClient {
 		sb.append("&signed=").append(parameter.getSigned());
 		sb.append("&sig=").append(StringHelper.urlEncodeUTF8(parameter.getSignature()));
 		sb.append("&ts=").append(parameter.getTimestamp());
-		sb.append("&u=").append(StringHelper.urlEncodeUTF8(parameter.getEncryptedUsername()));
+		sb.append("&u=").append(StringHelper.urlEncodeUTF8(parameter.getEncryptedUserIdentifier()));
 		sb.append("&display=").append(parameter.getDisplayMode()); // inline / dynamic / window
 		if (StringHelper.containsNonWhitespace(parameter.getWidth())) {
 			sb.append("&width=").append(parameter.getWidth());
diff --git a/src/main/java/org/olat/modules/edusharing/manager/EdusharingServiceImpl.java b/src/main/java/org/olat/modules/edusharing/manager/EdusharingServiceImpl.java
index 29e82d45e970a7cad357089445eec701c5efe7d8..199af65bd6197ce45e80f19ca7f7309584ce717c 100644
--- a/src/main/java/org/olat/modules/edusharing/manager/EdusharingServiceImpl.java
+++ b/src/main/java/org/olat/modules/edusharing/manager/EdusharingServiceImpl.java
@@ -75,6 +75,8 @@ public class EdusharingServiceImpl implements EdusharingService {
 	private EdusharingConversionService conversionService;
 	@Autowired
 	private EdusharingSecurityService securityService;
+	@Autowired
+	private EdusharingUserFactory userFactory;
 
 	@Override
 	public Properties getConfigForRegistration() {
@@ -162,7 +164,8 @@ public class EdusharingServiceImpl implements EdusharingService {
 		NodeIdentifier nodeIdentifier = conversionService.toNodeIdentifier(usage.getObjectUrl());
 		String courseId = conversionService.toEdusharingCourseId(usage.getOlatResourceable());
 		EdusharingSignature signature = securityService.createSignature();
-		String encryptedUsername = securityService.encrypt(edusharingModule.getRepoPublicKey(), viewer.getName());
+		String userIdentifier = userFactory.getUserIdentifier(viewer);
+		String encryptedUserIdentifier = securityService.encrypt(edusharingModule.getRepoPublicKey(), userIdentifier);
 		
 		GetRenderedParameter parameter = new GetRenderedParameter(
 				signature.getAppId(), 
@@ -176,7 +179,7 @@ public class EdusharingServiceImpl implements EdusharingService {
 				signature.getSigned(),
 				signature.getSignature(),
 				signature.getTimeStamp(),
-				encryptedUsername,
+				encryptedUserIdentifier,
 				"inline");
 		parameter.setWidth(widthChecked);
 		parameter.setHeight(heightChecked);
@@ -193,7 +196,8 @@ public class EdusharingServiceImpl implements EdusharingService {
 		NodeIdentifier nodeIdentifier = conversionService.toNodeIdentifier(usage.getObjectUrl());
 		String courseId = conversionService.toEdusharingCourseId(usage.getOlatResourceable());
 		EdusharingSignature signature = securityService.createSignature();
-		String encryptedUsername = securityService.encrypt(edusharingModule.getRepoPublicKey(), viewer.getName());
+		String userIdentifier = userFactory.getUserIdentifier(viewer);
+		String encryptedUserIdentifier = securityService.encrypt(edusharingModule.getRepoPublicKey(), userIdentifier);
 		String encryptedTicket = securityService.encrypt(edusharingModule.getRepoPublicKey(), ticket.getTooken());
 		
 		GetRenderedParameter parameter = new GetRenderedParameter(
@@ -208,7 +212,7 @@ public class EdusharingServiceImpl implements EdusharingService {
 				signature.getSigned(),
 				signature.getSignature(),
 				signature.getTimeStamp(),
-				encryptedUsername,
+				encryptedUserIdentifier,
 				"window");
 		parameter.setEncryptedTicket(encryptedTicket);
 		return client.getRenderUrl(parameter);
@@ -221,7 +225,7 @@ public class EdusharingServiceImpl implements EdusharingService {
 		CreateUsageParameter parameter = new CreateUsageParameter(
 				element.getIdentifier(),
 				element.getObjectUrl(),
-				identity.getName(),
+				userFactory.getUserIdentifier(identity),
 				conversionService.toEdusharingCourseId(ores)
 				);
 		client.createUsage(parameter);
@@ -248,7 +252,7 @@ public class EdusharingServiceImpl implements EdusharingService {
 		DeleteUsageParameter parameter = new DeleteUsageParameter(
 				usage.getIdentifier(),
 				usage.getObjectUrl(),
-				identity.getName(),
+				userFactory.getUserIdentifier(identity),
 				conversionService.toEdusharingCourseId(usage.getOlatResourceable())
 				);
 		client.deleteUsage(parameter);
diff --git a/src/main/java/org/olat/modules/edusharing/manager/EdusharingSoapClient.java b/src/main/java/org/olat/modules/edusharing/manager/EdusharingSoapClient.java
index 28f62c6c273e9116c5f883328d652356aaac896c..f2aec14e6d1484059099a797e65510db61bad095 100644
--- a/src/main/java/org/olat/modules/edusharing/manager/EdusharingSoapClient.java
+++ b/src/main/java/org/olat/modules/edusharing/manager/EdusharingSoapClient.java
@@ -37,7 +37,6 @@ import org.edu_sharing.webservices.usage2.Usage2;
 import org.edu_sharing.webservices.usage2.Usage2Exception_Exception;
 import org.edu_sharing.webservices.usage2.Usage2Service;
 import org.olat.core.id.Identity;
-import org.olat.core.id.User;
 import org.olat.core.logging.OLog;
 import org.olat.core.logging.Tracing;
 import org.olat.modules.edusharing.CreateUsageParameter;
@@ -59,6 +58,8 @@ class EdusharingSoapClient {
 	
 	@Autowired
 	private EdusharingModule edusharingModule;
+	@Autowired
+	private EdusharingUserFactory userFactory;
 
 	String createTicket(Identity identity) throws AuthenticationException {
 		return authenticate(identity).getTicket();
@@ -66,7 +67,7 @@ class EdusharingSoapClient {
 
 	private AuthenticationResult authenticate(Identity identity) throws AuthenticationException {
 		AuthByApp service = getAuthByAppService();
-		List<KeyValue> ssoData = getSSOData(identity);
+		List<KeyValue> ssoData = userFactory.getSSOData(identity);
 		AuthenticationResult result = service.authenticateByTrustedApp(edusharingModule.getAppId(), ssoData);
 		if (log.isDebug()) {
 			String logResult = new StringBuilder()
@@ -82,50 +83,6 @@ class EdusharingSoapClient {
 		return result;
 	}
 	
-	/**
-	 * Key are configured in edu-sharing configuration: edu-sharing-sso-context.xml
-	 *
-	 * @return
-	 */
-	private List<KeyValue> getSSOData(Identity identity) {
-		List<KeyValue> ssoData = new ArrayList<>();
-		
-		// mandatory
-		KeyValue userId = new KeyValue();
-		userId.setKey(edusharingModule.getAuthKeyUseriId());
-		userId.setValue(identity.getName());
-		ssoData.add(userId);
-		
-		// optional
-		User user = identity.getUser();
-		KeyValue lastname = new KeyValue();
-		lastname.setKey(edusharingModule.getAuthKeyLastname());
-		lastname.setValue(user.getLastName());
-		ssoData.add(lastname);
-		
-		KeyValue firstname = new KeyValue();
-		firstname.setKey(edusharingModule.getAuthKeyFirstname());
-		firstname.setValue(user.getFirstName());
-		ssoData.add(firstname);
-
-		KeyValue email = new KeyValue();
-		email.setKey(edusharingModule.getAuthKeyEmail());
-		email.setValue(user.getEmail());
-		ssoData.add(email);
-
-		KeyValue affiliationId = new KeyValue();
-		affiliationId.setKey("affiliation");
-		affiliationId.setValue(edusharingModule.getAuthAffiliationId());
-		ssoData.add(affiliationId);
-
-		KeyValue affiliationName = new KeyValue();
-		affiliationName.setKey("affiliationname");
-		affiliationName.setValue(edusharingModule.getAuthAffiliationName());
-		ssoData.add(affiliationName);
-		
-		return ssoData;
-	}
-	
 	boolean valdateTicket(String ticket) throws AuthenticationException {
 		AuthByApp service = getAuthByAppService();
 		return service.checkTicket(ticket);
diff --git a/src/main/java/org/olat/modules/edusharing/manager/EdusharingUserFactory.java b/src/main/java/org/olat/modules/edusharing/manager/EdusharingUserFactory.java
new file mode 100644
index 0000000000000000000000000000000000000000..70b315c0571056eb9fab494fac5664a977d0b953
--- /dev/null
+++ b/src/main/java/org/olat/modules/edusharing/manager/EdusharingUserFactory.java
@@ -0,0 +1,120 @@
+/**
+ * <a href="http://www.openolat.org">
+ * OpenOLAT - Online Learning and Training</a><br>
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); <br>
+ * you may not use this file except in compliance with the License.<br>
+ * You may obtain a copy of the License at the
+ * <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache homepage</a>
+ * <p>
+ * Unless required by applicable law or agreed to in writing,<br>
+ * software distributed under the License is distributed on an "AS IS" BASIS, <br>
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
+ * See the License for the specific language governing permissions and <br>
+ * limitations under the License.
+ * <p>
+ * Initial code contributed and copyrighted by<br>
+ * frentix GmbH, http://www.frentix.com
+ * <p>
+ */
+package org.olat.modules.edusharing.manager;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.edu_sharing.webservices.types.KeyValue;
+import org.olat.core.id.Identity;
+import org.olat.core.id.User;
+import org.olat.core.util.StringHelper;
+import org.olat.modules.edusharing.EdusharingModule;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+/**
+ * 
+ * Initial date: 7 Jan 2019<br>
+ * @author uhensler, urs.hensler@frentix.com, http://www.frentix.com
+ *
+ */
+@Component
+class EdusharingUserFactory {
+	
+	@Autowired
+	private EdusharingModule edusharingModule;
+	
+	String getUserIdentifier(Identity identity) {
+		String identifier;
+		
+		switch (edusharingModule.getUserIdentifierKey()) {
+		case "username":
+			identifier = identity.getName();
+			break;
+		case "email": 
+			identifier = identity.getUser().getEmail();
+			break;
+		default:
+			identifier = null;
+		}
+		
+		return StringHelper.blankIfNull(identifier);
+	}
+	
+	/**
+	 * Key are configured in edu-sharing configuration: edu-sharing-sso-context.xml
+	 *
+	 * @return
+	 */
+	List<KeyValue> getSSOData(Identity identity) {
+		List<KeyValue> ssoData = new ArrayList<>();
+		
+		// mandatory
+		KeyValue userId = new KeyValue();
+		userId.setKey(edusharingModule.getAuthKeyUseriId());
+		userId.setValue(getUserIdentifier(identity));
+		ssoData.add(userId);
+		
+		// optional
+		User user = identity.getUser();
+		
+		if (StringHelper.containsNonWhitespace(edusharingModule.getAuthKeyLastname())
+				&& StringHelper.containsNonWhitespace(user.getLastName())) {
+			KeyValue lastname = new KeyValue();
+			lastname.setKey(edusharingModule.getAuthKeyLastname());
+			lastname.setValue(user.getLastName());
+			ssoData.add(lastname);
+		}
+		
+		if (StringHelper.containsNonWhitespace(edusharingModule.getAuthKeyFirstname())
+				&& StringHelper.containsNonWhitespace(user.getFirstName())) {
+			KeyValue firstname = new KeyValue();
+			firstname.setKey(edusharingModule.getAuthKeyFirstname());
+			firstname.setValue(user.getFirstName());
+			ssoData.add(firstname);
+		}
+
+		if (StringHelper.containsNonWhitespace(edusharingModule.getAuthKeyEmail())
+				&& StringHelper.containsNonWhitespace(user.getEmail())) {
+			KeyValue email = new KeyValue();
+			email.setKey(edusharingModule.getAuthKeyEmail());
+			email.setValue(user.getEmail());
+			ssoData.add(email);
+		}
+
+		if (StringHelper.containsNonWhitespace(edusharingModule.getAuthAffiliationId())) {
+			KeyValue affiliationId = new KeyValue();
+			affiliationId.setKey("affiliation");
+			affiliationId.setValue(edusharingModule.getAuthAffiliationId());
+			ssoData.add(affiliationId);
+		}
+
+		if (StringHelper.containsNonWhitespace(edusharingModule.getAuthAffiliationName())) {
+			KeyValue affiliationName = new KeyValue();
+			affiliationName.setKey("affiliationname");
+			affiliationName.setValue(edusharingModule.getAuthAffiliationName());
+			ssoData.add(affiliationName);
+		}
+		
+		return ssoData;
+	}
+
+}
diff --git a/src/main/resources/serviceconfig/olat.properties b/src/main/resources/serviceconfig/olat.properties
index 7f18d40fa964fb65c8bc71961f4809e6e3924077..3216a91e7a4621d3a3f068d43dca455ff6135561 100644
--- a/src/main/resources/serviceconfig/olat.properties
+++ b/src/main/resources/serviceconfig/olat.properties
@@ -1446,13 +1446,18 @@ edusharing.app.id=
 # IP address of the OpenOLAT instance
 edusharing.host=
 edusharing.ticket.valid.seconds=10
+
+# User attribute to pass as userid to edu-sharing
+edusharing.user.identifier.key=username
+edusharing.user.identifier.key.values=username,email
+
 # Names of user attributes are configurable in edu-sharing. Use the same names here.
 edusharing.auth.key.userid=userid
 edusharing.auth.key.lastname=lastname
 edusharing.auth.key.firstname=firstname
 edusharing.auth.key.email=email
-edusharing.auth.affiliation.id=${instance.issuer.identifier}
-edusharing.auth.affiliation.name=${instance.issuer.identifier}
+edusharing.auth.affiliation.id=${instance.id}
+edusharing.auth.affiliation.name=${instance.id}
 
 ########################################
 # Options for monitoring