I've never heard of it being against the law to discuss compensation packages. Is this in writing from your employer?
From this (http://www.npr.org/2014/04/13/301989789/pay-secrecy-policies-at-work-often-illegal-and-misunderstood ) it does not appear to be the "law of the land" in the U.S.
If you signed a non-disclosure when you were hired, you may have given up your right to discuss certain topics. A good NDA is written in a way that requires the disclosing party to label / document / summarize the information that is confidential. Most employers don't have that clause, they just put in a vague statement that captures ever possible case. Signing an NDA like that should be a last resort (like you can't get any other job). It sets you up to be on the short-end-of-the-stick in a dispute. They can merely claim that it was "obvious" that compensation was confidential, although I would disagree with this expectation.
Step 1. Read any NDA you signed when you were hired
Step 2. Discuss with HR informing them that you'd like to seek outside advice. For example, you should have the right to get advice from a relative (e.g. parents) or a professional (e.g. tax attorney, tax accountant, or financial planner)
Rather than seek out an adversarial position, describe you legitimate concern and ask for permission.