You are free to publish works anonymously. This case is well-covered by international copyright laws (e.g. Art 7 (3) of the Berne Convention). Publishing anonymously is largely equivalent to publishing pseudonymously, except that the identity of a pseudonymous person is known. For example, what I publish here under the name "amon" is pseudonymous and keeps all my rights as if I had published under my real name. In contrast, the inventor of Bitcoin “Satoshi Nakamoto” has used a pseudonym with unknown identity, and is therefore (still?) anonymous.
Unfortunately anonymous works are a legal headache for users. The work is still copyright-protected like any other work. In most jurisdiction the copyright term ends 70 (or 50) years after the death of the author. For anonymous works the author is not known, and the term ends 70 (or 50) years after publication. However, the author may be identified later. If you (or later copyright holders such as your heirs) claim the copyright before it is expired, then the life + 70 years term applies again. A related problem are orphan works where the copyright holder is not known, therefore the copyright term cannot be calculated reliably.
So if you don't want to exercise your copyright it is best to actively disclaim copyright to the fullest extent possible, i.e. dedicate the work to the public domain and issue a fallback license for jurisdiction where this is not possible. The CC-0 is the best available legal instrument for that purpose.
You could in principle also use a MIT-style license such as the ISC which keeps the copyright intact. The copyright notice doesn't have to hold your real name, using "anonymous" should be fine. Compared to CC-0 users are required to keep the notice, which may actually be desirable as it becomes less likely that the work becomes an orphaned work. There ISC also includes a disclaimer which the CC-0 lacks. Of course trying to hold an anonymous author of a public domain work liable for anything is a bit silly, but you may still enjoy the minimal legal protection of a disclaimer.
Your idea of using a hash of your identity would allow you to publish anonymously, and would allow you to claim the copyright of the anonymous work later. However, this is not necessary for publishing anonymously, and only makes sense if you do plan to disclose your identity later. If you have published anonymously under the CC-0 you will already have disclaimed your copyright to the fullest extent possible, so disclosing your identity would have minimal value.