10. A system, comprising: a non-transitory memory; and one or more hardware processors coupled to the non-transitory memory and configured to read instructions from the non-transitory memory to cause the system to perform operations comprising: receiving a first password from a user; retrieving a second password for the user; decomposing the first and the second passwords into components contained in the passwords; determining whether the passwords are formed by the components using one or more rules of concatenation, insertion, and replacement; comparing similarities between the first password and the second password comprising identifying rules and components of the first and second passwords, comparing similarities of the rules and the components, and determining a first similarity score for the rules and a second similarity score for the components; determining a score between the first password and the second password based on the comparing; and comparing the score to a threshold score.
10. A system, comprising: a non-transitory memory; and one or more hardware processors coupled to the non-transitory memory and configured to read instructions from the non-transitory memory to cause the system to perform operations comprising: receiving a first password from a user; retrieving a second password for the user; decomposing the first and the second passwords into components contained in the passwords; determining whether the passwords are formed by the components using one or more rules of concatenation, insertion, and replacement; comparing similarities between the first password and the second password comprising identifying rules and components of the first and second passwords, comparing similarities of the rules and the components, and determining a first similarity score for the rules and a second similarity score for the components; determining a score between the first password and the second password based on the comparing; and comparing the score to a threshold score. 11. The system of claim 10 , wherein the operations further comprise accepting the first password if the score is greater than or equal to the threshold score.