pub fn key_hash(key: &str) -> StringExpand description
Blake2b-128 digest of a storage key as 32 lowercase hex characters.
Cache keys routinely embed user identifiers, so tracing events carry this
digest instead of the key (CWE-532). It is a correlator, not a
redaction: it is unkeyed and deterministic, so the same key hashes
identically in every process and matches the File backend’s on-disk
filename (and cachekit-py’s hashlib.blake2b(key, digest_size=16)) — and
for that same reason a low-entropy key such as user:42 can be recovered
from its digest by enumeration. Treat cachekit=debug output with the
care you give the keys themselves.