Visit Our UNIX and Linux User Community


Generate random numbers in script


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Generate random numbers in script
# 1  
Old 03-17-2013
Generate random numbers in script

i want to generate a random number through a script, and even if anyone reads the script, they wont be able to figure out what the random number is. only the person who setup the script would know it.

something like this could work: random

the full thread is here:

https://www.unix.com/shell-programmin...andomly-2.html

if anyone can modify the code to spit out a precise number only I (the script author) would know and no one else, even those who try to read the script.
# 2  
Old 03-17-2013
You've been down this road many times before.

Your script, by definition, would include the complete and unabridged method for generating this "secret" number. How would you conceal it? If the computer can decode it, so can they, no ifs or buts. You're not going to defeat this by being clever enough, the same way you can't change the value of pi by being clever enough.

The kind of security you want can be achieved by not letting their computer read it.

Last edited by Corona688; 03-17-2013 at 03:48 PM..
# 3  
Old 03-17-2013
Quote:
Originally Posted by Corona688
You've been down this road many times before.

Your script, by definition, would include the complete and unabridged method for generating this "secret" number. How would you conceal it? If the computer can decode it, so can they, no ifs or buts. You're not going to defeat this by being clever enough, the same way you can't change the value of pi by being clever enough.

The kind of security you want can be achieved by not letting their computer read it.
i understand what you're saying. but there's been quite a few things that i've read couldn't be done, but ended up being doable. they just required "being clever" enough, and having the excessive dedication time it takes to actually write something noone in their right mind would want to try to break unless given a massive monetary incentive to do so. and even then, you'd have to be in the mind of the coder to know what he's doing, especially if the script or code is large in size, void of comments, and not written in a way that makes it easily comprehended. but thanks for your input. much appreciated.
# 4  
Old 03-17-2013
I don't think you do. Have fun, though. I'm done here.
# 5  
Old 03-17-2013
Quote:
Originally Posted by SkySmart
i want to generate a random number through a script, and even if anyone reads the script, they wont be able to figure out what the random number is. only the person who setup the script would know it.
Quote:
Originally Posted by SkySmart
there's been quite a few things that i've read couldn't be done, but ended up being doable. they just required "being clever" enough, and having the excessive dedication time it takes to actually write something noone in their right mind would want to try to break unless given a massive monetary incentive to do so.
Perhaps what you are actually going for is to embed in a script a non-random, pre-determined number in an obfuscated manner? If so, that is doable. Otherwise, you are out of luck.

Regards,
Alister

Last edited by alister; 03-17-2013 at 04:57 PM..
# 6  
Old 03-17-2013
Quote:
Originally Posted by alister
Perhaps what you are actually going for is to embed in a script a non-random, pre-determined number in an obfuscated manner?

Regards,
Alister
if this is possible, i would be elated.
# 7  
Old 03-17-2013
It's possible, but as Corona pointed out, it's not at all secure. The best that you can hope for is to deter a lazy and incompetent adversary, someone who doesn't want to think through the code and who doesn't know enough to enable tracing (set -x) on your script.

You can't even do this in C or assembly language. If the instructions are there, they can be decoded.

It would probably be much more constructive if you described what you're defending against.
Regards,
Alister
This User Gave Thanks to alister For This Post:

Previous Thread | Next Thread
Test Your Knowledge in Computers #834
Difficulty: Medium
JSON supports comments.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Script to generate sequence of numbers

I need awk script to generate part number sequencing based on data in multiple columns like below Input File --------- Col A|Col B|Col C| 1|a|x| 2|b|y| |c|z| | |m| | |n| And out put should be like 1ax 1ay 1az 1am 1an 1bx 1by (6 Replies)
Discussion started by: aramacha
6 Replies

2. UNIX for Advanced & Expert Users

UNIX script for making random numbers without repetition

Hello, I have a column which have 7200 numbers and I am deciding to pick up 1440 numbers randomly without any reputation? Could any one let me know which script in unix will be work for my case? Regards Sajjad (17 Replies)
Discussion started by: sajmar
17 Replies

3. Shell Programming and Scripting

Need to generate a file with random data. /dev/[u]random doesn't exist.

Need to use dd to generate a large file from a sample file of random data. This is because I don't have /dev/urandom. I create a named pipe then: dd if=mynamed.fifo do=myfile.fifo bs=1024 count=1024 but when I cat a file to the fifo that's 1024 random bytes: cat randomfile.txt >... (7 Replies)
Discussion started by: Devyn
7 Replies

4. Shell Programming and Scripting

Generate 16 digit positive random Numbers

Hi Unix Gurus, I have a requirement to generate positive random 16 and 13 digit numbers. Here is the script I have so far..... number=$RANDOM$RANDOM$RANDOM$RANDOM; let "number %= 10000000000000"; echo $number But sometimes it is generating negative numbers and also 15 digit... (8 Replies)
Discussion started by: scorpioraghu
8 Replies

5. Programming

generate array of random numbers

hi guys, I am writing a c program that generates a two dimensional array to make matrix and a vector of random numbers and perform multiplication. I can't figure out whats wrong with my code. It generates a matrix of random numbers but all the numbers in the vector array is same and so is the... (2 Replies)
Discussion started by: saboture88
2 Replies

6. Programming

Generate random number

I saw this formula to generate random number between two specified values in shell script.the following. $(((RANDOM%(max-min+divisibleBy))/divisibleBy*divisibleBy+min)) Give a example in book. Generate random number between 6 and 30.like this. $(((RANDOM%30/3+1)*3)) But I have a... (1 Reply)
Discussion started by: luoluo
1 Replies

7. Shell Programming and Scripting

shell script to auto process ten random files and generate logs

Hello member's I'm learning to script in the ksh environment on a Solaris Box. I have 10 files in a directory that I need to pass, as input to a batch job one by one. lets say, the files are named as follows: abcd.txt ; efgh.bat ; wxyz.temp etc. (random filenames with varied extensions ).... (1 Reply)
Discussion started by: novice82
1 Replies

8. Shell Programming and Scripting

how do i generate random integer using only shell script

Hi All, I need to generate 4 digit random no using only shell script. Please help in this ASAP. Thanks in advance... Regards, sridhar. (1 Reply)
Discussion started by: sridhusha
1 Replies

9. Shell Programming and Scripting

Generate a random password

Hello All... Can someone help me generate a random password which will be 7 characters long which contains alpha-numeric characters using shell script. I am looking to store the output of the script that generates the password to a variable within a script and use it as the password. ... (5 Replies)
Discussion started by: chiru_h
5 Replies

10. Programming

How to generate a random number?

How to generate a random integer with specific range(for example, from 1 to 1000)? Also, how to convert a floating point number into a integer? (2 Replies)
Discussion started by: MacMonster
2 Replies

Featured Tech Videos