IND-ID-CPA Security ⇒ IND-sID-CPA Security (Selective)
IND-ID-CPA Security implies IND-sID-CPA Security (Selective).
Statement
Migrated verbatim from identity-based-encryption:
In the selective variant, the adversary must commit to the challenge identity before the public parameters are generated. This is a strictly weaker notion than adaptive IND-ID-CPA.
Migrated verbatim from identity-based-encryption:
is negligible. Any IND-ID-CPA-secure scheme is also IND-sID-CPA-secure; the converse requires a complexity-leveraging argument that incurs a polynomial security loss in .
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.
This relation is stated on 2 pages; the statements above are all of them.
Recorded during migration and not fixed — these are claims about the source text, not changes to it:
- ‘strictly weaker’ asserts both an implication and a separation; no citation for either.
- Security notions, not wiki pages - no slugs.
- No citation (this is folklore but carries no ’- standard’ label, contrary to the folklore policy in CLAUDE.md).