> ## Documentation Index
> Fetch the complete documentation index at: https://docs.flexagon.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Java Cryptography Extension (JCE) unlimited strength policy files

> Install JCE unlimited strength jurisdiction policy files when Java rejects large encryption keys.

> [!NOTE]
>
> This is not necessary for newer JDK versions. If you see `limited` and `unlimited` folders under `jre/lib/security/policy`, then your JDK is generally set up for it.

## Problem

`java.security.InvalidKeyException: Illegal key size or default parameters`

**OR**

`javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure`

**OR**

Unable to reach a settlement: `[aes128-cbc, aes128-ctr, blowfish-cbc, cast128-cbc, cast128-ctr, idea-cbc, idea-ctr, serpent128-cbc, serpent128-ctr, 3des-cbc, 3des-ctr, twofish128-cbc, twofish128-ctr, arcfour, arcfour128]` and `[aes256-ctr]`.

## Solution

Due to import control restrictions by the governments of a few countries, the jurisdiction policy files shipped with the JDK from Sun Microsystems specify that "strong" but limited cryptography may be used. That means the JDK has a deliberate key size restriction by default. So you cannot perform an encryption with a key more than 128 bits.

An "unlimited strength" version of these files indicating no restrictions on cryptographic strengths is available for those living in eligible countries (which is most countries). But only the "strong" version can be imported into those countries whose governments mandate restrictions. The JCE framework will enforce the restrictions specified in the installed jurisdiction policy files.

You may also encounter this issue when accessing SSL resources (for example RiouxSVN) which use encryption keys with a size greater than the default limit.

To overcome this restriction you need to download and install the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files into the JRE.

1. Download according to your JRE version:
   1. [Java 6 Policy Files](http://www.oracle.com/technetwork/java/javase/downloads/jce-6-download-429243.html)
   2. [Java 7 Policy Files](http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html)
   3. [Java 8 Policy Files](http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html)
2. Unzip into `<JRE_HOME>/lib/security` (overwrite existing files)
3. Restart your JVM