On this page:
1 Allowing world access to /  etc
2 Allowing MD5 digest

Adjusting system permissions and lowering security

This slide explains which alterations to the system are necessary for setting up the online access

    1 Allowing world access to /etc

    2 Allowing MD5 digest

1 Allowing world access to /etc

As suggested on Arch website:

mkdir -p /etc/.java/.systemPrefs
chmod 755 -R /etc/.java

2 Allowing MD5 digest

Remember: everything should be done in a dedicated virtual machine.

It seems that Banco do Brasil uses an insecure method of signing .jar files. This is forbidden in Ubuntu and in other modern Linux systems. In order to allow Banco do Brasil to bypass those security requirements, edit the file /etc/java-8-oracle/security/java.security and comment out the line: jdk.jar.disabledAlgorithms=...

This step compromises the security of your system against MITM attacks. But it seems to be necessary for Banco do Brasil to function. Remember we are doing everything in a dedicated virtual machine, which should only be used for communications with Banco do Brasil. This, however, does not protect agains MITM attacks. Some comfort can be achieved by thinking that it is very hard to break out of a virtual machine.