Add error check to decipher

[Julian-Chu]

Description

• add error check for decipher
• move decipher to own package
• update makefile

Issues to fix

Please link issues this PR will fix:
#75

if no relevant issue, but this will fix something important for reference
, please free to open an issue.

Reminding

Something you can do before PR to reduce time to merge

• run "make build" to build the code
• run "make format" to reformat the code
• run "make lint" if you are using unix system
• run "make test-integration" to pass all tests

[kkc]

LGTM, thanks a lot!