Recharge Cards Algorithms
 

Do you ever wonder if you can crack the algorithm that recharge cards are based on? lets say alfa prepaid recharge cards. There must be some algorithm by which the cards are produced.. definitely not random...does anyone know any famous algorithms?

they could be using several algorithms for types of cards(for example even numbered cards have one algorithm, and odd numbered cards have another), and they could be using several algorithms in succession for every card to get a password for every registration code... it's near impossible to just guess things like that

14 characters is too much for the pattern to be cracked, also, as mentioned by Mr_J, there could be several patterns applied to get one recharge card.

I wanna crack a 7 digit algorithm..not 14 ... But in general are there any known algorithms to be used in the market or each company just decides on one?

if they were known, they wouldn't use them anymore

the people who invented the famous algorithms, cannot break their own encryption, even if they knew it is their algorithm being used, because the variables or "the key" used to generate this number is known only to the person who made the encryption. You don't know how many algorithms they used, in what order, and what is the key for each... la2 ken 3 numbers, you won't break it :p

it is known that all doors have keys, that does not mean that you can build a key that will open for you the bank doors at night...

edit: more details, keys generated for a serial number, or for a given sentence in case of encryption, does not simply transform each number letter into a mirror. like it does not turn all A into c and all z into d(that was actually used 2300 years ago by caesar) in modern algorithms, the position of the letter or number in the sentence changes, and then depending on the letter things might change, and then they add to all that some jumbled up formula and turn the whole thing into marsian, and then they take that and do something else entirely...

several layers of encryption and transformations are applied, to break it you need to uncover every single one, and do the reverse process...

fine..but still i have a question.. when u type in the code and press submit..does the website acceess the database and verify if the code exists? or does teh browser perform a certain algorithmic test and if the code meets vertain requirements it will recharge?

not the browser dude!

the server decodes the number using the private key of the company depending on the appropriate algorithm!!

This is not encryption, its kind of random number generation.
Even if you knew the algorithm you cannot generate valid serials and use them.
What Alfa or MTC do is generate the random serials, put them in a database and release them in the market. Even if you generate a valid serial, it will only work if it matches one of the released serials in the database. Each period of time, they realese a number of serials.
What you can do is to hack the server and compromise the database or at least have indirect access to it...

Mathematically speaking...how big of a sample is needed to crack a 14 digit algorithm?

what do you mean 14 digits algorithm? an algorithm that generates 14 digits or...?

in any case it can be infinity... there is no limit to mathematical formulas you can throw on something...