encode-decode password in apps

[merel]

SHA/MD5 are one-way hashing algorithms, not suitable for two-way encryption/decryption. In your case probably some simple XOR can be used. Is the pin code always in 1 number + * + 4 numbers format?

Hello admin,

password is number of user + "*" + user password ( 4 or 8 digit )
for example:

2*1111 or 2*11112222
3*1111 or 3*11112222


Originally I wanted to use RSA encryption/decription but I did not find the solution in pure LUA.
The second idea was to use openssl and os.execute but solution in lua is better.

Thank you verry much.