Hi, I have gone through some implementations of DES/3DES and found that the des_key_schedule is generated just before the data is given to the encryption API. I have got some clarifications and I would be thankful if somebody could clarify these: 1. Isn't it advisable to generate the des_key_schedule only once and use the same one for the encryption of all the data. Since des_key_schedule generation is dependent only on DES Key, it will not change unless the key changes. So, isn't it advisable to generate the des_key_schedule only when the DES key changes. Doing this for every data may take some finite amount of processing time, which may reduce the performance. Can anybody give some comments on this. 2. If des_key_schedule is generated only once when the key changes, we need to store the corresponding des_key_schedule, until the key changes. I have seen that des_key_schedule takes a lot of memory that needs to be kept apart for it until the key expires. Is this the reason that the des_key_ is generated only when the data is to be encrypted/decrypted. Could anybody comment on the processing time taken by des_key_schedule against the memory it requires. Thanks in advance. Regards, Prasanna. ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
