Strength-based password expiration

A method comprising:

• receiving, by a computing device, an entry of a string of inputs as a new password that is associated with an access privilege;
• measuring, by the computing device, a complexity of the string of inputs of the new password, wherein the measuring of the complexity of the string of inputs comprises:
• determining, a respective entropy value for individual ones of inputs of the string of inputs based at least in part on a symbol set used in the individual ones of inputs, wherein the respective entropy value is different for at least two of the individual ones of inputs;
• updating, as the string of inputs is received, the complexity of the string of inputs by summing instances of the respective entropy value for the individual ones of the inputs;
• and
• dynamically determining, by the computing device, an expiration of the new password based at least in part on the complexity of the string of inputs.

A method, comprising:

• determining, via one or more computing devices, an entropy value of a string of inputs of a shared secret, the entropy value for the string of inputs being based on a symbol set used in the string of inputs;
• as a result of the string of inputs changing, updating a total entropy value for the changed string of inputs by multiplying the entropy value by a quantity of inputs of the changed string of inputs;
• and
• dynamically determining as the string of inputs is received an expiration of the shared secret based at least in part on the total entropy value of the string of inputs.

One or more non-transitory computer-readable media storing computer-executable instructions that, when executed on one or more processors, performs acts comprising:

• receiving an entry of a string of inputs as a new password that is associated with an access privilege;
• as a result of receiving the entry:
• determining an entropy value for individual inputs of the string of inputs of the new password, based on a symbol set used in the string of inputs;
• updating, as the string of inputs is received, a total entropy value for the string of inputs by aggregating the entropy value of the individual inputs of the string of inputs;
• and
• dynamically determining an expiration of the new password based at least in part on the total entropy value of the string of inputs.