[Cryptography] Digital dyes for tracing digital leaks ?

[Henry Baker]

If I'm trying to find a leak in my sewer or water pipe, I
can choose from a large variety of colored and/or fluorescent
dyes, which are easily detected when they appear outside the
pipe.

Ditto for radioactive tracers for even tinier leaks.

Are there standard digital *codes* (other than 0xdeadbeef)
for performing the same function in detecting use-after-free
and other types of data leaks?

Ideally, the codes should be random-looking enough that
they are picked up as possible crypto keys by key-hunting
software, but also easily traced back to different sources.

I was thinking along the lines of linear codes -- e.g.,
some sort of CRC code, where a long enough subsequence
can not only determine the polynomial, but also the
position (i.e., exponent).

Thus, "uninitialied" memory would be initialized to such
a code in such a way that if some of the same bit sub-
sequences showed up again, it might be indicative of a
data leak.