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If you want to work in IT security, the main certifications that is necessary to progress in the field is CISSP (Certified Information Systems Security Professional). In my company, that is step one, required certification before we will even consider the rest of your resume. Then I would get SANS GSEC certification. I'm not trying to shill for SANS, but you can get some useful certification through SANS, either through live training or online learning (where applicable). Unlike many so-called schools, SANS actually has value in the real world, and beyond GSEC (Global Information Assurance Certification Security Essentials Certification - you can see why they use the acronym), you can also demonstrate that you have practical skills and knowledge of web app penetration testing (GWAPT), web app security (GWEB) or secure coding (GSSP), for example.
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