Harshal Tupsamudre

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In 2013, the US National Security Agency proposed two new families of lightweight block ciphers: SIMON and SPECK. Currently, linear and differential cryptanalytic results for SIMON are available in the literature but no fault attacks have been reported so far on these two cipher families. In this paper, we show that these families of ciphers are vulnerable(More)
Researchers have demonstrated the ineffectiveness of deterministic countermeasures and emphasized on the use of randomness for protecting cryptosystems against fault attacks. One such countermeasure for AES was proposed in LatinCrypt 2012, which masks the faulty output with secret values. However this countermeasure does not affect the erroneous byte in the(More)
The user interface for inputting text-based passwords has been the same for past 40 years. Today, technology enables the development of intuitive, interactive and responsive interfaces that can help users in creating and remembering more secure passwords. In this paper, we exploit the power of modern-day technologies and develop two novel interfaces, (i)(More)
Decades of psychology and decision-making research show that everyone makes decisions differently; yet security messaging is still one-size-fits-all. This suggests that we can improve outcomes by delivering information relevant to how each individual makes decisions. We tested this hypothesis by designing messaging customized for stable personality traits—(More)
Markov-based strength meters provide more accurate estimate of password strength as opposed to rule-based strength meters. However, we observed that these meters assign very high scores to slightly altered weak passwords. It is important to score modified variants of weak passwords more conservatively as the existing password cracking tools generate such(More)
The graphical pattern unlock scheme which requires users to connect a minimum of 4 nodes on 3X3 grid is one of the most popular authentication mechanism on mobile devices. However prior research suggests that users' pattern choices are highly biased and hence vulnerable to guessing attacks. Moreover, 3X3 pattern choices are devoid of features such as longer(More)
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