# Authentication by Keystroke Dynamics: The Influence of Typing Language
## 3 Methodology
### Bilingual Keystroke Dynamics Dataset (BKSD)
#### 3.1.1 Data Collection  
**Password:** In order to compare a password entered in Arabic and in English, we selected a meaningful word with the same character sequence in both languages; see Figure 2. The password is a mix of letters, numbers and a special character, and is at least 8  
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**Paper** & **Field** & **Input Type** & **Application** \\ \hline [PERSON] [12] & security & smartphone & verification \\ [PERSON] [13] & security & smartphone & authenticating \\ [PERSON] [15] & dataset collection & keyboard, smartphone, tablet & any \\ [PERSON] [7] & security & keyboards & verification \\ [PERSON] [16] & security & tablet & authentication \\ [PERSON] [17] & clock testing & keyboard & any \\ [PERSON] [18] & security & keyboard with sensor & authentication \\ [PERSON] [19] & health & smartphone & brain health \\ [PERSON] [20] & security & smartphone & authentication \\ [PERSON] [21] & HCI & keyboard & gender, age, handedness \\ [PERSON] [22] & HCI & keyboard & language \\ [PERSON] [23] & emotion & smartphone & stress \\ [PERSON] [25] & HCI & smartphone & age, gender, user experience \\ [PERSON] [26] & security & smartphone & authentication \\ [PERSON] [28] & health & keyboard & Parkinson’s disease \\ [PERSON] [29] & health & keyboard & mental fatigue \\ [PERSON] [30] & HCI & smartphone & age, gender \\ [PERSON] [31] & security & keyboard & authentication \\ [PERSON] [32] & HCI & keyboard & education level \\ [PERSON] [33] & security & smartphone & authenticating \\ [PERSON] [34] & security & smartphone & authenticating \\ [PERSON] [35] & security & keyboard, mouse & authenticating \\ [PERSON] [36] & security & smartphone & authentication with privacy \\ [PERSON] [37] & security & keyboard & authentication with privacy \\ \hline \hline \end{tabular}
\end{table}
Table 1: Summary of papers presented in the literature review.  
characters long, fulfilling the general requirements for a strong password. We do not use a capital letter as those do not exist in Arabic. In English, the password is \"thing-173\", and in Arabic, it is \"\({}_{\text{VY}}\) - \({}_{\text{L}}\)\". The letter positions for the English and Arabic passwords are the same on the keyboard used, and follow the same sequence. Both words are meaningful in both languages. This is an intentional choice, as it allows us to ascertain whether the most important factor is the letter positions on the keyboard or the language being used.  
**Phrase:** Finding meaningful words in both languages with corresponding keystroke patterns is difficult, and so we do not follow the procedure outlined above for an entire phrase. Instead, we constructed two sentences, one in English and one in Arabic, where each sentence was composed of meaningful words separated by spaces, and some characters within each word overlap. The English sentence was \"the queue shiver light false\", and the Arabic sentence was \"\({}_{\text{w}}\)\". The overlapping characters are highlighted in red in Figure 3.  
The most common bigrams in the English language present in the words selected in our dataset are listed in Table 2, with the corresponding most frequent bigrams in Arabic. The rank column indicates the rank of the bigram as measured by its frequency. As we only collect the overlapping characters, as highlighted in Figure 3, we denote the available bigrams in our dataset in Table 2 using an asterisk. Note that the dataset bigrams in English are more commonly used than the dataset bigrams in Arabic.  
Figure 3: Overlapping characters, shown in red, in the phrase chosen in BKSD.  
Figure 2: Password chosen in the dataset BKSD, with characters highlighted.