[tahoe-dev] proposal: add padding

[Zooko O'Whielacronx]

No, no, we rely on the correctness of our encryption to hide all
information about the plaintext from an attacker who doesn't know the
encryption key. Therefore, the pad bytes are all just zero bytes, and
we believe that this pattern gives nothing useful to the cryptanalyst.

(Our encryption is currently AES. I hope in the future to upgrade it
to AES⊕XSalsa20 — see #1164 and wiki:OneHundredYearCryptography.)

https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1164# use
XSalsa20+AES-128 encryption

https://tahoe-lafs.org/trac/tahoe-lafs/wiki/OneHundredYearCryptography

Regards,

Zooko