MUSCLE Doubt regarding Smart Card

[Sriram V]

Hi, Can someone answer this question please...   I was trying to update the System Key of Gemplus's MPCOS-EMV cards (in file EFKey 3F01h) using the Update Binary command. Though the update command succeeded, I was not able to authenticate to the card using the new system key that I used in the update command (obviuously the card has written something else into the file). The card returned the error: 94 08h  i.e Key file selection error.   Since we have to write the 16 bytes 3DES key as 2 DES keys separately, which part of the 16 bytes (Key type part 1 or Key type part 2) should be written first and which second (I tried both ways but the result was the same)? Also in which order (LSB first or MSB first)? Kindly send me full information about this operation.   Best Regards, Sriram V