[Cryptography] Low grade randomness for padding.

[Richard Outerbridge]

> On 2021-02-09 (40), at 20:22:23, Donald Eastlake <d3e3e3 at gmail.com> wrote:
> 
> On Tue, Feb 9, 2021 at 4:15 PM Phillip Hallam-Baker
> <phill at hallambaker.com> wrote:
> ...
>> The ciphertext uses a more flexible tag-length-value encoding. The basic layout will be:

Of course, the old fashioned method was to pad with zeroes to a boundary, with the last byte
containing 0x01.  Unfortunately, for eg AES this implies an additional known plaintext block
of some { 0x0000  0000 0000 0000 0000 0000 0000 0001 } bytes when no padding (1/16 or
1 : 15 odds)  is required.
__outer