Reports the sizes fixed by a FIPS 204 or FIPS 205 parameter set, so a
caller never has to hard-code them. Use it to check key material before
fipskey(), to size storage for signatures, or to compare
parameter
sets: an SLH-DSA signature is 7,856 to 49,856 bytes where an ML-DSA one
is 2,420 to 4,627.
Arguments
- scheme
Scheme name, as in
fipskg().
Value
A named integer vector of five byte counts: public_key,
secret_key, signature, seed and rnd (the
per-signature
randomness the scheme consumes).
Details
The sizes are the standards' tables (FIPS 204 Table 2, FIPS 205 Table 2)
as the compiled code uses them. seed is the key-generation input of
fipskg(); rnd is the per-signature
randomness (32 bytes
for ML-DSA's rnd, \(n\) bytes for SLH-DSA's opt_rand), which the
deterministic variants replace with a fixed value. XMSS is not covered:
its sizes follow from the tree height of pqckg(). An
unknown
scheme, or anything but one string, is refused.
Examples
fipssz("ML-DSA-65")
#> public_key secret_key signature seed rnd
#> 1952 4032 3309 32 32
fipssz("SLH-DSA-SHAKE-128s")
#> public_key secret_key signature seed rnd
#> 32 64 7856 48 16
# An SLH-DSA signature is far larger than an ML-DSA one at the same
# security level, which is the price of dropping the lattice
# assumption.
fipssz("SLH-DSA-SHAKE-128s")[["signature"]] >
fipssz("ML-DSA-44")[["signature"]]
#> [1] TRUE
# Every standardised set at once.
sapply(setdiff(pqcbknd(), "xmss-sha256"), fipssz)["signature", ]
#> ML-DSA-44 ML-DSA-65 ML-DSA-87 SLH-DSA-SHA2-128s
#> 2420 3309 4627 7856
#> SLH-DSA-SHA2-128f SLH-DSA-SHA2-192s SLH-DSA-SHA2-192f SLH-DSA-SHA2-256s
#> 17088 16224 35664 29792
#> SLH-DSA-SHA2-256f SLH-DSA-SHAKE-128s SLH-DSA-SHAKE-128f SLH-DSA-SHAKE-192s
#> 49856 7856 17088 16224
#> SLH-DSA-SHAKE-192f SLH-DSA-SHAKE-256s SLH-DSA-SHAKE-256f
#> 35664 29792 49856
# XMSS has no fixed sizes here.
try(fipssz("xmss-sha256"))
#> Error : unknown scheme 'xmss-sha256'. The standardised schemes are: ML-DSA-44, ML-DSA-65, ML-DSA-87, SLH-DSA-SHA2-128s, SLH-DSA-SHA2-128f, SLH-DSA-SHA2-192s, SLH-DSA-SHA2-192f, SLH-DSA-SHA2-256s, SLH-DSA-SHA2-256f, SLH-DSA-SHAKE-128s, SLH-DSA-SHAKE-128f, SLH-DSA-SHAKE-192s, SLH-DSA-SHAKE-192f, SLH-DSA-SHAKE-256s, SLH-DSA-SHAKE-256f. For the stateful hash-based scheme use pqckg().