Caesar cypher

Caesar cypher has its name origin because of the ruler of Rome, who gave his orders to generals in encrypted form. If such order was intercepted by enemies, they will not be able to read it.

An algorithm that was used by Caesar cypher was a simple one by today's standards of encryption. Each letter in original message was replaced by a letter certain number of steps away.

By how many steps it is needed to shift letters was known by sender and a reader. Sender would encrypt the message by replacing all the letters of that message with letters that are certain number of steps away, a receiver to decrypt such a message would needed to reverse this process.

The problem with this cypher it is weak. Somebody that receives an encrypted message in this form, needs only 26 combinations at maximum to decrypt it. Not much time is required to do so.

YouTube video

Comments

Post a Comment

Popular posts from this blog

Absolute and relative path in HTML pages

HTML documents can have relative or absolute links to other web pages. Relative links keeps a visitor on the same web site. Relative links are pointers to other web pages on the same web site. They just contain this page filename. Absolute links on other hand contain full path including protocol and domain name to access the page. Absolute links can point to the same web site or they can point to a different web site.
Read more

Errors

It is a good idea to send errors in production environment to error log. Errors may contain sensitive information. Even so errors maybe helpful to development team or to QA team, errors need to be suppressed in production environment for viewing by everyone. Errors are good way to troubleshoot an issue therefore only trusted people can have access to this information. If not a trusted person get an access to this information, this information maybe used against the company and for a personal benefit. What to do in a case when there are more servers than one? Even so it is possible to inspect the log files in a single server, however it is impossible to do so when there is more than one server is available and web traffic is redirected to a different server each time. Log aggregation is needed in this case. All of the logs will be send to a central location. Logs may contain sensitive information. Please consult your company lawyer of how long logs can be stored, because logs can be use...
Read more

goto PHP operator

goto operator will skip execution of code and continue execution of a code that follows a label to which goto operator points to. If code has many goto operators, than this code probably needs a revision. It is possible to write code that executes without goto operators.
Read more