Check out my favourite article to get a taste of it. https://www.wired.com/2015/09/tricky-encryption-stump-quantu...
Some others to get a good sample:
[1]: https://www.wired.com/2016/09/using-math-repair-650-year-old...
[2]: https://www.wired.com/2015/12/outsiders-crack-a-50-year-old-...