I agree with Adnan's answer that it's highly unlikely that RSA 2048 bit keys can be cracked in "a matter of seconds" but you should be considering more than just key strength.
A well-resourced group with time, talent and money is going to try many approaches to get what they want: key cracking, key stealing, host compromise, social engineering, etc.
You should also consider how long those messages need to be secure. We could make a long list of crypto systems that were considered very secure at one time but have been weakened by Moore's law and scrutiny. Credit cards have a relatively short lifespan before they expire, your SSN could be sensitive for 80-100 years.