# Super Safe RSA 2 - Crypto

> Wow, he made the exponent really large so the encryption MUST be safe, right?! Connect with nc 2018shell2.picoctf.com 56543

If we connect to it, we get the following numbers:
```
c: 74656558022839055957486462819905995876187919411516725694171429102789712929327942602783390443413015793339709672458190916198217092854563013073826016059117106865706437459318250499145704904019507722273390686196228735285877381812173288926254273484207110105872784138331460508370948963482034330305034653674346440792
n: 148337238837980204604258481398486555479662772411127669544511411414637480091964615739652008000282038439580320179857917659146369849900257414100209029025277317009008322530433114360958279216638713900178224553226111248718730750329686617313196229443362042513004804865365680353556694701248340698570731626730407309679
e: 44107111604677056428020584204530379886662319696898620571797517039794933771031851731366993910333034515954372329293242617510494976349334211644884162360431185438204499339781140455266740769128912694626003486588778554609303393869982440909134987801843941738926751485241331998121883562658508426442151685340795506049
```
Since e is not a usual value here, and it is very large, I google about that and find that RSA with such large e is easily prone to [Wiener Attack](https://en.wikipedia.org/wiki/Wiener%27s_attack).

Then I find these [scripts](https://gist.github.com/mananpal1997/73d07cdc91d58b4eb5c818aaab2d38bd) online. After changing to my values and then running it, I get the flag: picoCTF{w@tch_y0ur_Xp0n3nt$_c@r3fu11y_5261983}

Original writeup (https://github.com/liuhack/writeups/blob/master/2018/picoCTF/Super_safe_RSA2/README.md).