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           _    _    _____      _____     _____   
    ___   | || | || |  __ \\   |  ___||  |__  //  
   /   || | || | || | |  \ ||  | ||__      / //   
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   \__ ||  \____//  |_____//   |_____||  /_____|| 
    -|_||   `---`    -----`    `-----`   `-----`  
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Text this: Formal analysis and systematic construction of two-factor authentication scheme