About DH and Shamir secret sharing

Hi, I have two problems. The first is about Diffie-Hellman algorithm. In
PKIX part1, now
rfc2459, the algorithm is described as:

DomainParameters ::= SEQUENCE {
        p            INTEGER, -- odd prime, p=jq+1
        g            INTEGER, -- generator, g
        q            INTEGER, -- factor of p-1
        j            INTEGER OPTIONAL, -- subgroup factor
        validationParms    ValidationParms OPTIONAL }

ValidationParms    ::= SEQUENCE {
        seed            BIT STRING
    pgenCounter   INTEGER }

while in certificate management protocol, now rfc2510, the algorithms is
described as
below:
OID:    1.2.840.10046.2.1
DHParameter ::= SEQUENCE {
        prime INTEGER, -- p
        base  INTEGER  -- g
}

So which is the most up to date description, and which should I
implement?

The second is about Shamir secret sharing. If I want to encode a secret
split in ASN.1, I should have the AlgorithmIdentifier of the algorithm,
which needs an OID,
and parameters. I once searched an OID for the algorithm from
http://www.alvestrand.no/~hta/objectid/top.html , but when I have a
discussion with the
OID contact person, he told me it was just to identify a secret split,
not intend to identifier
the algorithm description. So is there any AlgorithmIdentifier
description to the Shamir
secret sharing, and how to identify a specific secret split?

Any suggestions will be appreciated, and best regards.

Xiong Shaojun