diff --git a/src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java b/src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java
index 5143190fd..04885ad10 100644
--- a/src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/ContactDetailsActivity.java
@@ -28,6 +28,7 @@ import android.widget.ImageButton;
 import android.widget.LinearLayout;
 import android.widget.QuickContactBadge;
 import android.widget.TextView;
+import android.widget.Toast;
 
 import org.openintents.openpgp.util.OpenPgpUtils;
 
@@ -455,13 +456,13 @@ public class ContactDetailsActivity extends XmppActivity implements OnAccountUpd
 	}
 
 	private void onOmemoKeyClicked(Account account, String fingerprint) {
-		Log.d(Config.LOGTAG,"on omemo key clicked");
 		final XmppAxolotlSession.Trust trust = account.getAxolotlService().getFingerprintTrust(fingerprint);
-		if (trust != null) {
+		if (trust != null && trust == XmppAxolotlSession.Trust.TRUSTED_X509) {
 			X509Certificate x509Certificate = account.getAxolotlService().getFingerprintCertificate(fingerprint);
 			if (x509Certificate != null) {
-				Log.d(Config.LOGTAG, "certificate for fingerprint " + fingerprint + " was not null");
 				showCertificateInformationDialog(CryptoHelper.extractCertificateInformation(x509Certificate));
+			} else {
+				Toast.makeText(this,R.string.certificate_not_found, Toast.LENGTH_SHORT).show();
 			}
 		}
 	}
diff --git a/src/main/java/eu/siacs/conversations/utils/CryptoHelper.java b/src/main/java/eu/siacs/conversations/utils/CryptoHelper.java
index d1b90ab64..5c504e040 100644
--- a/src/main/java/eu/siacs/conversations/utils/CryptoHelper.java
+++ b/src/main/java/eu/siacs/conversations/utils/CryptoHelper.java
@@ -1,21 +1,17 @@
 package eu.siacs.conversations.utils;
 
 import android.os.Bundle;
-import android.util.Log;
 import android.util.Pair;
 
 import org.bouncycastle.asn1.x500.X500Name;
 import org.bouncycastle.asn1.x500.style.BCStyle;
 import org.bouncycastle.asn1.x500.style.IETFUtils;
 import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
-import org.bouncycastle.jce.PrincipalUtil;
 
 import java.security.MessageDigest;
-import java.security.SecureRandom;
 import java.security.cert.CertificateEncodingException;
 import java.security.cert.CertificateParsingException;
 import java.security.cert.X509Certificate;
-import java.security.cert.X509Extension;
 import java.text.Normalizer;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -33,8 +29,6 @@ import eu.siacs.conversations.xmpp.jid.Jid;
 public final class CryptoHelper {
 	public static final String FILETRANSFER = "?FILETRANSFERv1:";
 	private final static char[] hexArray = "0123456789abcdef".toCharArray();
-	private final static char[] vowels = "aeiou".toCharArray();
-	private final static char[] consonants = "bcdfghjklmnpqrstvwxyz".toCharArray();
 	final public static byte[] ONE = new byte[] { 0, 0, 0, 1 };
 
 	public static String bytesToHex(byte[] bytes) {
@@ -68,22 +62,6 @@ public final class CryptoHelper {
 		return result;
 	}
 
-	public static String randomMucName(SecureRandom random) {
-		return randomWord(3, random) + "." + randomWord(7, random);
-	}
-
-	private static String randomWord(int lenght, SecureRandom random) {
-		StringBuilder builder = new StringBuilder(lenght);
-		for (int i = 0; i < lenght; ++i) {
-			if (i % 2 == 0) {
-				builder.append(consonants[random.nextInt(consonants.length)]);
-			} else {
-				builder.append(vowels[random.nextInt(vowels.length)]);
-			}
-		}
-		return builder.toString();
-	}
-
 	/**
 	 * Escapes usernames or passwords for SASL.
 	 */
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index 2666e98d4..1035ff833 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -567,4 +567,5 @@
 	<string name="certificate_o">Organization</string>
 	<string name="certificate_sha1">SHA1</string>
 	<string name="certicate_info_not_available">(Not available)</string>
+	<string name="certificate_not_found">No certificate found</string>
 </resources>