How to get the last 32 bits in ANSI X9.19 MAC generation ( very urgent )

Question

I am trying to generate the MAC of 256bits of data according to ANSI X9.19 standard.
I am trying to do this in the following way
1) Encrypt the whole 256 bits using DES in CBC mode ( blocksize=64bits and hence 4 blocks)
2) Taking the last 8 bytes (i.e., last 64bits) I am decrypting it with DES in ECB mode using another key
3)Taking the ciphertext from above step, i am encrypting the ciphertext using DES ECB mode with key used in step1
Is the above steps are correct according to ANSI X9.19 MAC standard.
If so how to generate the final 32 bits from the 64 bits of the final block according to the X9.19 standard.

Answer 1

Please see the paper at the following location
http://citeseer.ist.psu.edu/cache/papers/cs2/112/http:zSzzSzwww.scs.carleton.cazSz~paulvzSzpaperszSzElecLetters.pdf/a-key-recovery-attack.pdf
The above pdf file describes the X9.19 MAC generation and at the end of the file there is the diagram that describes the process.
2) Taking the last 8 bytes (i.e., last 64bits) I
am decrypting it with DES in ECB mode usinganother
key Really? Decrypt something that wasn't encrypted?
aking the ciphertext from above step
What ciphertext? Do you mean plaintext? Or do you
mean you encrypted in the previous step?
, i am
encrypting the ciphertext using DES ECB mode with
key used in step1 Encrypting ciphertext? why? it's already encrypted.
Is the above steps are correct according to ANSI
X9.19 MAC standard.
Almost certainly not, it reads like sheer nonsense to
me.
If so how to generate the final 32 bits from the 64
bits of the final block according to the X9.19
standard.
You carry out the steps in the standard. I haven't
read it. Have you?