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Develop an algorithm to generate TANs in ColdFusion, Java, JavaScript, PHP

$30-250 USD

Closed
Posted almost 7 years ago

$30-250 USD

Paid on delivery
I am looking for someone who uses his/her high maths expertise to create an algorithm to deliver pseudo-random TAN codes. The algorithm starts off with a seed and is able to generate any n-th code. Repeatedly retrieving a code for the same position returns the same value. Repetition of the same value at different position: not before 10^12 values or better. It is able to generate the next code based on the last one or on the position/index provided as input. The code itself is a string consisting of a set of chars. The algorithm is able to check a given code if it is a valid code of the sequence created by seed. The algorithm is able to save and restore its state (serializable). It does not precalculate a list of keys. Repetition of codes is ok, Some terms: - Position: whatever needed to indicate the n-th code in the sequence. Integer, structure, whatever is needed. - Alphabet, a set of one or many of those: - Lower: all lower case chars a-z - Upper, all upper case char A-Z - Digits, 0-9 - Special, non-alfanum chars - Safe, eliminates dangerous chars like ilIO0S5 I could imagine something like this in pseudo-code: Class TANgen. Constructor (seed, alphabet, codelength) // this initializes the algorithm to be able to start. It shuld assume that we will retrieve one code after another, so the class memorizes how many codes have already been generated. string function get () string function get (position) // get the next code or the code at position. string function get_next (position) string function get_next (code) // both functions get the next code, following the one given either by a position or a code string[] function get (position, count) string[] function get (code, count) // get count codes starting with the one given by either a position or a code position function validate (code) // checks the code and returns its position or null if not valid boolean function validate (code, position) // wrapper for validate() != null position function validate (code, position, windowsize) // returns the position of a code if found at position, where position is the middle position of a sliding window. So like code in (code[position-windowsize],…,code[position-1],code[position],code[position+1],…,code[position+windowsize]) function save() function load() Maybe someone has already done that or knows where I can start off. Any help or pointers to source is highly appreciated. Thank you.
Project ID: 14457530

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6 proposals
Remote project
Active 7 yrs ago

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6 freelancers are bidding on average $183 USD for this job
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Greetings sir, i am an expert freelancer for this job and your 100% satisfaction is assured if you allow me to serve. Here is the reason. Why you should pick me? a) I am a very expert and have the same kind of experience of 5 years. b) I work very hard (16+ hours a day and 7 days a week) and also very fast so... it will be done very soon than most of the other providers c) And most important part is my policy: "I will give you (to my client) life time support (as long as you keep relation with me). And fix any bugs/problem without any cost. So, don't ever worry about me” Please sir, leave a reply ASAP, as I am waiting for your kind reply
$250 USD in 3 days
4.8 (27 reviews)
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Ready to discuss further details as I am an expert in custom projects and scripts .
$222 USD in 5 days
4.2 (2 reviews)
2.4
2.4
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Hi I just read your requirement. I have long experience in this field. I can provide you good solution. And I can work full time or part time for you. Thanks
$235 USD in 3 days
0.0 (0 reviews)
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Hello Sir, We have gone through the details you have provided and we have already worked on a similar project before and can deliver as u have mentioned and would be pleased to work on this with you to deliver the results that you have expected and we have already worked on a similar project before and can deliver as u have mentioned We are sure you will not be disappointed if you give us this opportunity. Our team is experienced, creative & efficient enough to get your job done well. We have an impeccable record and all our clients enjoy working with us, we are sure that you will too, our prices are cheapest in market. I am ready to discuss with you with best Regards
$208 USD in 6 days
0.0 (0 reviews)
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Flag of SWITZERLAND
Richterswil, Switzerland
5.0
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Member since Jul 26, 2012

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