`ltrace ./keygen`providing any input that is 7 characters or longer we can see that it's comparing it with **laska!!**
![](https://i.imgur.com/61DBYkY.png)
running the binary with that input returns this string:1639171916391539162915791569103912491069173967911091119123955915191639156967955916396391439125916296395591439609104911191169719175
Then using this tool [https://www.dcode.fr/code-ascii](https://www.dcode.fr/code-ascii) gives us the flag **syskronCTF{7HIS-isn7-s3cUr3-c0DIN9}**