No reduction from HE to SZK

A reduction of class unstated from HE to SZK would imply szk-neq-bpp.

Statement

Migrated verbatim from homomorphic-encryption § Other results:

  • HE → rerandomizable encryption → SZK BPPBL13

Notes

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:

  • SUSPECTED MATH ERROR / SEVERE MIS-SUMMARY. The bullet reads as an implication chain ‘HE rerandomizable encryption SZK != BPP’. BL13 proves a LIMIT ON PROVABLE SECURITY: a compact homomorphic bit-encryption scheme for a sensitive function class cannot be proved message-indistinguishable beyond AM cap coAM by general adaptive reductions, and beyond SZK by constant-query reductions. That is a barrier, not an implication, and ‘rerandomizable encryption’ does not appear in the paper’s abstract at all.
  • AM cap coAM — BL13’s headline bound — is nowhere on the page. Neither is the constant-query-vs-adaptive distinction, which separates TWO different barriers with two different classes.
  • The reduction class is the load-bearing part of BL13 (general adaptive vs constant query complexity) and is entirely absent.
  • Formatted as a chain of arrows, which under the target model must be SPLIT into separate reductions with separate citations — but here there is nothing to split into, because the chain is not what the paper says.