Whatsapp help

Hello guys I am here for serious help as I am a complete noob my problem start a month ago when my whatsapp stop working asking me to re-register only to promote me to download the latest whatapp version which is incompatible with my ios (I have iphone 4) and I can’t get the appropriate ios . I started seeking help but no one was able to help so I start to analyze the problem in my hand after awhile I find out that manipulating whatsapp plist file enable me to open the app and read the message offline and now I want to check what happen if I re enter my owncountrycode and ownphonenumber correctly I check that it base 64 but somehow encrypted so it became obvious that reverse engineering skills is in demand but I am not one so I start looking in the net your book look the best place to start but I realize that diving into this new field would take me years so I would really appreciate help and direction.
What I was thinking is someone with reverse engineering skills could have better understanding of how country code and phone number is encrypted and save to plist file as base64 and mimic the process with python script .
Like this (“7”>>> “UGsK1DrKOrZw4w09V/cQeA==”)

I know that I may not explain myself probably and lets say that I want to figure out how phone number and country code is saved to plist is there any encryption and how to mimic the process by python so that I can put back my country code and phone number which was deleted without re-register .

I just checked on iPhone 4 whatsapp works perfectly well. I deleted it then re registered all works well

Plus the latest update works well.

Thanks. Nickin

Thank you very much Nickin ,
But there is small catch here I am not willing to update my ios not now and I was thinking of something related more to reverse engineering I know that your answer represent the shortest line between two points but ios update pose a problem to me which made me take this path in the first place , I just wont to edit whatsapp plist file to enter my right country code and phone number there is no problem with the jid because I can used ifile to enter the string value in plain text this is not the case with country code and phone number which are save in base64 which seem to me encrypted I have this intuition if I enter it in the right way I may get the app work again since I still get the notifications ,may be this turn to be true or false but I am a noob and the only way for me to know is if someone with the right skills and wellness to help provide his generous help .

Mattu, update iOS to 7.1.2 & do your RE part it won’t make any difference in your studies for your model of iPhone4.

Hope to find someone to help you out.

Thanks, NickIN

Any more help please from reverse engineering elite …