There is a tool called gron which makes JSON greppable. So with your example,

% gron 11165436.json | head               
json = [];
json[0] = {};
json[0].Obj1 = [];
json[0].Obj1[0] = {};
json[0].Obj1[0].Obj11Attributes = {};
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj1 = {};
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj1.Obj11AttributesObj
+1Key1 = "1";
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj1.Obj11AttributesObj
+1Key2 = "3";
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj2 = {};
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj2.Obj11AttributesObj
+2Key1 = "9";
[download]

Then, if you just wanted a list of keys, you could strip away the values,

% gron 11165436.json | perl -pE 's/ =.+//' | head
json
json[0]
json[0].Obj1
json[0].Obj1[0]
json[0].Obj1[0].Obj11Attributes
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj1
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj1.Obj11AttributesObj
+1Key1
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj1.Obj11AttributesObj
+1Key2
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj2
json[0].Obj1[0].Obj11Attributes.Obj11AttributesObj2.Obj11AttributesObj
+2Key1
[download]