Password management and verification with a blockchain

An apparatus, comprising:

• a hardware processor configured to:
• determine whether one or more password strings are related to one or more existing passwords, wherein the one or more password strings are transmitted from a user device,
• hash the one or more password strings to create one or more respective password hash values,
• determine whether the one or more password hash values match any internal password hash values of an internal password history chain stored in an internal blockchain,
• determine whether the one or more password hash values match any external password hash values of an external password history chain stored in an external blockchain,
• and
• responsive to the determining that the one or more password hash values do not match any internal password hash value and any external password hash values, store the one or more password hash values as a new password in a block of one or more of the internal blockchain and the external blockchain, wherein all password hash values for all user devices that utilize the one or more of the internal blockchain and the external blockchain are stored in the block.

A non-transitory computer readable storage medium storing instructions that, when executed, are configured to cause a processor to perform:

• determining whether one or more password strings are related to one or more existing passwords, wherein the one or more password strings are transmitted from a user device;
• hashing the one or more password strings to create one or more respective password hash values;
• determining whether the one or more password hash values match any internal password hash values of an internal password history chain stored in an internal blockchain;
• determining whether the one or more password hash values match any external password hash values of an external password history chain stored in an external blockchain;
• and
• responsive to the determining that the one or more password hash values do not match any internal password hash value and any external password hash values, storing the one or more password hash values as a new password in a block of one or more of the internal blockchain and the external blockchain, wherein all password hash values for all user devices that utilize the one or more of the internal blockchain and the external blockchain are stored in the block.