Ask HN: Is encryption safe enough to publish encrypted copy of private data

If we have private data, encrypted using best practices (salted, 2048bit keys, private keys stored off line, etc), is it considered safe to post this encrypted data in a publicly accessible location?

Imagine if everyone encrypted and published a tarball of their email history. Would this data be considered "vulnerable" to attacks ?

Any form of encryption can be cracked eventually, given enough time and processing power. What if a new type of supercomputer is invented tomorrow that can crack 2048 bit in minutes? Not publishing your data would give you the opportunity to re-encrypt using the latest method.