{ cmp1999(1), cmp2000(2) },
    sender              GeneralName,
    recipient           GeneralName,
    messageTime     [0] GeneralizedTime         OPTIONAL,
    protectionAlg   [1] AlgorithmIdentifier     OPTIONAL,
    senderKID       [2] KeyIdentifier           OPTIONAL,
    recipKID        [3] KeyIdentifier           OPTIONAL,
    transactionID   [4] OCTET STRING            OPTIONAL,
    senderNonce     [5] OCTET STRING            OPTIONAL,
    recipNonce      [6] OCTET STRING            OPTIONAL,
    freeText        [7] PKIFreeText             OPTIONAL,
    generalInfo     [8] SEQUENCE SIZE (1..MAX) OF
                     InfoTypeAndValue     OPTIONAL
    }

    Z