Q:

Getting 'Coikoe' in http request instead of 'Cookie'

Our website is receiving http requests from a user which contains 'Coikoe' tag instead of 'Cookie'.
Http request object received from firefox is mentioned below :
com.pratilipi.servlet.UxModeFilter doFilter: REQUEST : GET http://www.pratilipi.com/books/gujarati HTTP/1.1
Host: http//www.pratilipi.com
User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Referer: http://www.pratilipi.com/?action=login
Coikoe: _gat=1; visit_count=1; page_count=2
X-AppEngine-Country: XX
X-AppEngine-Region: xx
X-AppEngine-City: XXXXXX
X-AppEngine-CityLatLong: 12.232344,12.232445

Http request object received from google chrome is mentioned below :
com.pratilipi.servlet.UxModeFilter doFilter: REQUEST : GET http//www.pratilipi.com/books/hindi HTTP/1.1
Host: http//www.pratilipi.com
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.132 Safari/537.36
Referer: http//www.pratilipi.com
Accept-Language: en-US,en;q=0.8,ta;q=0.6
Coikoe: _gat=1; visit_count=1; page_count=1
X-AppEngine-Country: XX
X-AppEngine-Region: xx
X-AppEngine-City: xxxxxx
X-AppEngine-CityLatLong: 12.232344,12.232445

User is using window 8 system.
Question : Why is this happening and how can I solve it? I have never seen anything like this before. Anyone has come accross anything like this
Thank You

A:

This user will be using some sort of privacy proxy. 
The same happens for the Connection request header as explained in Cneonction and nnCoection HTTP headers: the proxy mangles the header so it won't be recognized by the receiver, but by merely shuffling some letters around the TCP packet's checksum will remain the same.  

