Index: src/java/org/jamwiki/utils/Encryption.java
===================================================================
--- src/java/org/jamwiki/utils/Encryption.java	(revision 1494)
+++ src/java/org/jamwiki/utils/Encryption.java	(working copy)
@@ -85,9 +85,17 @@
 		try {
 			md = MessageDigest.getInstance("SHA-512");
 		} catch (NoSuchAlgorithmException e) {
-			logger.severe("JDK does not support the SHA-512 encryption algorithm");
-			throw e;
+			logger.warning("JDK does not support the SHA-512 encryption algorithm");
 		}
+		// fallback to weaker encryption algorithm if nothing better is available
+		if (md == null) {
+			try {
+				md = MessageDigest.getInstance("SHA-1");
+			} catch (NoSuchAlgorithmException e) {
+				logger.severe("JDK does not support the SHA-1 encryption algorithm, either");
+				throw e;
+			}
+		}
 		try {
 			md.update(unencryptedString.getBytes("UTF-8"));
 		} catch (UnsupportedEncodingException e) {