Decentralized applications built on blockchain platforms can potentially transform many industries and sectors, in actual fact they already have carved a huge impact over finance, social media, entertainment and more. The problem our research focuses on is decentralized IDentity Management Systems (IDMSs) and their applications, which they open the feasibility gate for Self-Sovereign Identity (SSI). We address the main challenges in the development of SSI systems, in managing management cryptographic functions (issuance, storage, recovery, ..etc.), revocation of credentials and selective disclosure capabilities. We also have proposed solutions and methodologies to overcome some of those challenges.