@cpio: As far as I can tell the current kernel was compiled without those modules:
tc@box:~$ wget -qO - http://distro.ibiblio.org/tinycorelinux/3.x/release/src/kernel/config-2.6.33.3-tinycore | grep -iE 'serpent|rmd160'
# CONFIG_CRYPTO_RMD160 is not set
# CONFIG_CRYPTO_SERPENT is not set
tc@box:~$
So I doubt that either of them would be included in any extension. Building those modules yourself is not that tricky: there is a
Wiki page for starters and several threads here in the forum (just search for it).
You might want to suggest to have them included in the
next build (e.g. TC 4.x).