CryptoCurrency Certification Consortium (C4) | 12,658 followers on LinkedIn. Establishing cryptocurrency standards. The industry leader in professional blockchain certifications. #LearnMoreWithC4 | The CryptoCurrency Certification Consortium (C4 for short) establishes cryptocurrency standards that help ensure a balance of openness & privacy, security & usability, and trust & decentralization. C4 issues certification exams that test cryptocurrency knowledge in professionals, such as Certified Bitcoin Professionals and Certified Bitcoin Experts. C4 also annually produces Blockchain Training Conference.