Hash function ⇒ PRF
Hash function implies PRF.
Statement
Migrated verbatim from impagliazzos-five-worlds § Breaking up Cryptomania:
Early work of GKM+00 lays out how these different primitives relate to each other. Importantly, there is a large gap between OWF and TDP in Cryptomania: OWFs imply PRGs, PRFs, SKE, MACs, and digital signatures, but not public-key encryption. TDPs (equivalently, the existence of PKE or OT) unlock the full power of asymmetric cryptography. OT is complete for all of MPC, so Cryptomania is also the world where general secure computation is possible.
Notes
source: folklore: the claim carried no citation on the page it was
migrated from, and none was invented.
class: unstated: no citing page says which notion of reduction is meant.
Recording a class the wiki does not state would add a claim.
Recorded during migration and not fixed — these are claims about the source text, not changes to it:
- DISJUNCTIVE BUNDLE: “OWFs imply PRGs, PRFs, SKE, MACs, and digital signatures” is five separate one-hypothesis reductions; this record isolates OWF ⇒ PRF. Must not be stored as one hyperedge with five conclusions.
- No citation on the clause — the canonical sources (HILL99 for OWF⇒PRG, GGM86 for PRG⇒PRF, Rom90/NY89 for OWF⇒signatures) are absent. GKM+00 is cited earlier in the paragraph but for a different claim.
- None of the five conclusions is wikilinked here — they are bare abbreviations in prose.
- Hypothesis OWF is only reachable via the hash-function page alias.