The present invention relates to systems and methods for securing web-based transactions. A system for securing web-based transactions includes a credential strengthener coupled to a client browser. The client browser communicates with a web server in a web-transaction. The credential strengthener converts a web credential entered by a user at the client browser to a higher entropy web credential associated with the user. The client browser then returns the higher entropy web credential for further use in the web transaction. A method for securing a web-based transaction includes steps of converting a web credential entered by a user at a client browser to a higher entropy web credential associated with the user, and returning the higher entropy web credential to the web server to continue the web transaction.