> On May 1, 2023, at 11:55 PM, Ilari Liusvaara <[email protected]> wrote: > >> >> Also tried to figure out what Ilari’s 1212481536 is. Most KEM and >> curve IDs are small integers. > > It is offset between HPKE kem and COSE crv spaces. > > Such offset needs to exist, because this mapping needs a contiguous > block of 65536 crv, and values like 4 are already allocated on COSE > side, but available for allocation on HPKE side. > > And to not hog 1-, 2- or 3-byte space, the offset needs to be at > least 65536. And for keeping it in 5-byte space (which is plentiful), > the offset can be at most 4294901760. > > BTW, 1212481536 = 0x48450000. And in ASCII, 0x48 => H, 0x45 => E.
Yeah, I figured it was some offset and looked for candidate ID spaces but couldn’t find one. Maybe it’s in the HPKE Python code, not RFC 9180? Document reference for the HPKE KEM ID space? LL
_______________________________________________ COSE mailing list [email protected] https://www.ietf.org/mailman/listinfo/cose
