Recalculating Guarded Fields

[pnganga]

RECALCULATING GUARDED FIELDS

I have a question on recalculating guarded fields. From what I have learnt from old threads, I am supposed to open the calculator, input field 0, ID, select hash, input data from the guarded field, then put the results in the guard field.

SAMPLE:
PHONE: MW3020
VERSION: DI4,6J
0: 083A05083015240709
ID: DB9FF729695A
HASH: 21
FIELD: 16178
FIELD DATA: 02
CRYPT RESULTS: 5BEC1606
CRYPT SPECIAL RESULTS: ECBA452B

This information is from a working phone. What is puzzling me is that the phone's field 5256 has 5BEC16061CF6A53C96. This is close to the "crypt results", but is longer.

When I put this data in the calculator and use decrypt or decrypt special, the calculator says "incorrect checksum - you entered invalid data"

When I edit the field to have "crypt results" or "crypt special results", the phone becomes simlocked without sim.

Questions:
Why is the phone working with "invalid data?"
When calculating, am I supposed to use crypt or crypt special?
When checking checksums, do I use decrypt or decrypt special?
What is the difference between crypt and crypt special? Why do they give different results? Are they for different phones or different fields?

I would be very grateful if any experienced member could shed some light on this matter. I have noted that most questions on the forum are on "simlocked without sim" phones, and I am sure that if all newbies like me could learn how to do this properly, we would not have to keep repeating the same questions.

Many thanks to all the Gurus on this forum for their invaluable help to newbies.

Peter

[vozice_09]

>>Why is the phone working with "invalid data?"
In your example:
crypted value 5BEC16061CF6A53C96, after decrypt you get value 02
you must in calc set checksum length (in protected fields is checksum 8 bytes)

>>When calculating, am I supposed to use crypt or crypt special?
>>When checking checksums, do I use decrypt or decrypt special?
Special crypt/decrypt use only with field 5709

>>What is the difference between crypt and crypt special? Why do they give >>different results? Are they for different phones or different fields?
difference is only one XOR function

[pnganga]

We,, thats interesting. I guess thats why my values were coming out different. I will recalculate with the info you have given. Thank you very much!
Peter

[pnganga]

Thanks vozice_09,
Your message helped, now my simlocked phone is free.
Just one more question, about field 5709. For all the other fields, we recalculate using data from their correspondent fields. Now, what is the correspondent field for 5709? Or, where do I get the data to crypt or check this field?

Thanks for your help,
Peter

[vozice_09]

Plain 5709 is not stored in phone... You must know this value...