Identity authentication blockchain

A system comprising:

• one or more processors;
• and
• memory storing instructions that, when executed by the one or more processors, cause the one or more processors to:
• store a blockchain ledger referencing hashes associated with verifications and denials, wherein an individual verification of the verifications is associated with a first hash of first personal information associated with a user;
• receive, from a computing device, a verification request message including personal information of a requesting user;
• receive a cryptographic salt;
• hash, using a hashing function and the cryptographic salt, the personal information as hashed personal information;
• compute a plurality of similarity scores between the hashed personal information and the hashes stored on the blockchain ledger, wherein a first similarity score of the plurality of similarity scores indicates a similarity value between the hashed personal information and an individual hash of the hashes stored on the blockchain ledger, wherein the computing includes computing a similarity value of the hashed personal information to a second hash associated with a denial;
• deny an entity based at least in part on determining that the similarity value meets or exceeds a threshold value;
• and
• transmit, based at least in part on the denying and to a device associated with the entity, an indication of the denial.

A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to:

• access a blockchain ledger stored in a memory, wherein the blockchain ledger indicates verifications and denials of identities and hashes associated therewith, and further wherein an individual verification of the verifications is associated at least one hash corresponding to an identity that was verified;
• receive, from a computing device, personal information associated with an entity;
• hash, as hashed personal information and using a cryptographic salt, the personal information;
• search the blockchain ledger for at least one match between the hashed personal information and the hashes;
• determine a similarity value of the hashed personal information to a hash associated with a denial;
• deny the entity based at least in part on determining that the similarity value meets or exceeds a threshold match value;
• and
• transmit, to the computing device, a denial based at least in part the denying.