5.2, Paragraph before conclusion

[nathanhere]

For slight increase in readability / flow:

Instead of:
"That's a huge number, consisting of 39 digits, a number large enough that trying all combinations is considered impossible. This attack allows them to do it in at most"

Consider:
"That's a huge number—consisting of 39 digits. It's so large that trying all combinations is considered impossible. This attack, however, allows them to do it in at most"