Assembly is done using the provided Assembler:

public void assemble( ModuleAssembly module )
{
  [...snip...]

    new RiakEntityStoreAssembler().withConfig( config, Visibility.layer ).assemble( module );
      [...snip...]

}

Here are the available configuration properties:

public interface RiakEntityStoreConfiguration extends ConfigurationComposite
{
    /**
     * List of Riak Protocol Buffer hosts.
     *
     * Each entry can contain either an IP address / hostname
     * or an IP address / hostname followed by a column and the host's port.
     *
     * Defaulted to 127.0.0.1 if empty.
     *
     * @return List of Riak nodes
     */
    @UseDefaults
    Property<List<String>> hosts();

    /**
     * User name to use for authentication.
     *
     * @return Authentication user name
     */
    @Optional
    Property<String> username();

    /**
     * Password to use for authentication.
     *
     * @return Authentication password
     */
    @Optional
    Property<String> password();

    /**
     * Type of the keystore used for server certificate authentication.
     *
     * @return Type of the keystore used for server certificate authentication
     */
    @Optional
    @OneOf( { "PKCS12", "JCEKS", "JKS" } )
    Property<String> truststoreType();

    /**
     * Path of the keystore used for server certificate authentication.
     *
     * @return Path of the keystore used for server certificate authentication
     */
    @Optional
    Property<String> truststorePath();

    /**
     * Password of the keystore used for server certificate authentication.
     *
     * @return Password of the keystore used for server certificate authentication
     */
    @Optional
    Property<String> truststorePassword();

    /**
     * Type of the keystore used for client certificate authentication.
     *
     * @return Type of the keystore used for client certificate authentication
     */
    @Optional
    @OneOf( { "PKCS12", "JCEKS", "JKS" } )
    Property<String> keystoreType();

    /**
     * Path of the keystore used for client certificate authentication.
     *
     * @return Path of the keystore used for client certificate authentication
     */
    @Optional
    Property<String> keystorePath();

    /**
     * Password of the keystore used for client certificate authentication.
     *
     * @return Password of the keystore used for client certificate authentication
     */
    @Optional
    Property<String> keystorePassword();

    /**
     * Password of the key used for client certificate authentication.
     *
     * @return Password of the key used for client certificate authentication
     */
    @Optional
    Property<String> keyPassword();

    /**
     * Riak Bucket where Entities state will be stored.
     *
     * Defaulted to "polygene:entities".
     *
     * @return Riak bucket name
     */
    @UseDefaults( "polygene:entities" )
    Property<String> bucket();

    /**
     * Cluster execution attempts.
     *
     * @return Cluster execution attempts
     */
    @Optional
    Property<Integer> clusterExecutionAttempts();

    /**
     * Minimum connections per node.
     *
     * @return Minimum connections per node
     */
    @Optional
    Property<Integer> minConnections();

    /**
     * Maximum connections per node.
     *
     * @return Maximum connections per node
     */
    @Optional
    Property<Integer> maxConnections();

    /**
     * Block on maximum connections.
     *
     * @return Block on maximum connections
     */
    @UseDefaults
    Property<Boolean> blockOnMaxConnections();

    /**
     * Connection timeout.
     *
     * @return Connection timeout
     */
    @Optional
    Property<Integer> connectionTimeout();

    /**
     * Idle timeout.
     *
     * @return idle timeout
     */
    @Optional
    Property<Integer> idleTimeout();
}

All authentication related properties are optional. By default no authentication is used. As soon as you provide a username, authentication is set up. Please note that you should then at least provide truststoreType, truststorePath and truststorePassword. To use client certificate authentication, set keystoreType, keystorePath, keystorePassword and keyPassword.