Base64
Base64 usually used to reduce the use of special characters.
The length of Base64 hash to be in a multiple of 4.
If the resulting output is only 3 characters long, for example, an extra = is added as padding, and so on.
jadu101@htb[/htb]$ echo aHR0cHM6Ly93d3cuaGFja3RoZWJveC5ldS8K | base64 -d
https://www.hackthebox.eu/Hex
Hex encodes each character into its hex order in the ASCII table.
For example, a is 61 in hex, b is 62, c is 63, and so on.
If the hash is consisted of 0-9 and a-f then it could be hex encoded.
To encode in hex:
jadu101@htb[/htb]$ echo https://www.hackthebox.eu/ | xxd -p
68747470733a2f2f7777772e6861636b746865626f782e65752f0aTo decode in hex:
jadu101@htb[/htb]$ echo 68747470733a2f2f7777772e6861636b746865626f782e65752f0a | xxd -p -r
https://www.hackthebox.eu/Caesar/Rot13
Caesar cipher shifts each letter by a fixed number.
Most common of which is rot13, which shifts each character 13 times forward.
To rot13 encode:
jadu101@htb[/htb]$ echo https://www.hackthebox.eu/ | tr 'A-Za-z' 'N-ZA-Mn-za-m'
uggcf://jjj.unpxgurobk.rh/To rot13 decode:
jadu101@htb[/htb]$ echo uggcf://jjj.unpxgurobk.rh/ | tr 'A-Za-z' 'N-ZA-Mn-za-m'
https://www.hackthebox.eu/Online tool is available such as rot13.