[Retr0id]

harvest-now-decrypt-later attacks aren't much of a concern for modern symmetric cryptography. heck, even known-broken ciphers like rc4 aren't easy to break in a non-interactive setting with modest ciphertext sizes and no key reuse.

[beloch]

It all depends on who the message needs to be secure from, and for how long.

[Retr0id]

Sure, but for symmetric ciphers it's not hard to hit the "by anyone, for my lifetime" threshold. NIST does not define a sunset date for AES-256, for example.