This php script provides a unique random key with 32 characters and can be used to avoid the system to pass some primary keys across the url, by example.

A simple algorithm to convert decimal numbers to binary; pointless since most languages have an inbuilt function but was used for learning about algorithm design.

The decrypter for the simple encrypter I posted earlier - Takes the encrypted text from a text file - "encrypt.txt" which the encrypter automatically writes to.

A quick implementation of an encrypter which can't be cracked by frequency analysis.

The method 'removeDoubles' uses a HashSet to remove double elements from a list without creating another list. The first occurrences of the multiple elements are kept, others will be removed. The order of the list will be preserved. The parameter list's iterator must support remove. Example of use is given in the main-method.

This little function does great for passwords, usernames, files, and anything else you need a random string for.

I'm in the process of writing test fixtures for our rails site. A lot of my tests require authentication, so I've had to port our permissions system into a fixture. Rather than type out all of the information for the fixture, I decided to create a nested loop that will take care of this for me.

There's probably a rake task for this, but I wasn't able to find it, so I came up with my own solution. You'll have to do a little cleanup when it's done, however some slight mods to this loop could even eliminate that.

This is a simple script to generate a random alphanumeric string.

This is a random password generator that produces understandable passwords based on word lists. I've only included a 3 entry world list because you should chose a list based on your password requirements and your users. If you need to generate passwords that are 14 characters in length, you will want a different list than if you're generating 8 character passwords. And depending on your users, you may want to use certain lists. The list I use is about 4000 words that are 5-7 characters long, all well-known words that have had potentially objectionable content removed. For security reasons I don't want to include this list.

A note on security: though this generates relatively strong passwords for the average user, they are particularly susceptible to brute-force attacks. This is even more an issue if somehow your word list gets compromised. I would not recommend using this function for anything where a highly secure password is needed.

A note on choosing your list: You'll also see that I've built the system to avoid generating passwords with zeros and ones in them. This is because zero and upper-case "o" can be confused as can one, lower-case "L" and upper-case "i." When choosing my word list I was also sure to strip out all words that start with the letter "o" or "i" (to prevent the optional ucfirst() from creating 0/O and I/1 confusion) and words that contain the letter "L" (to prevent l/1 confusion). I find that this greatly helps with preventing confusion, but again weakens the security of the passwords some. It's your choice.

This is a very convenient way to remove all doubles from a List in Java. The only prerequisite is that the elements in the list have proper equals and hashCode methods.

It work by using the constructor of a Set that takes a Collection as an argument.

I poured the snippet in a little program so can run it straight away.