Scratch

Try a simple one. Start by taking apart the string into a list. When doing this, put it against a ascii to convert to binary. Once in binary, using hashing techniques. For a real world example, you could refer to this wikipedia page on MD5 - http://en.wikipedia.org/wiki/MD5#Algorithm Once implemented, you can hash a string with MD5 (or any algorithm of your choice) However, you must code in a truth table so you can do bitwise operations.

Yeah, that is why I explained that you needed to separate the string into binary, with a table. Should I post a project showing that type thing?

Alright. I gotta build a table though. (with a C program, of course!)

Did you read the page on wikipedia I linked earlier? Also, I put the binary project online (assuming I didn't make any careless mistakes).

Do you know bitwise operations?

G0D_M0D3 wrote:

SeptimusHeap wrote:

I understand very little of that article 

Sorry if this seems spammy, but is the block library dead?

I remember you as a dev, am I right? Or was that a mod, or website...

Anyways, is it dead?

I was a Panther dev.

And yes, Sparks still updates the library.

bobbybee wrote:

Do you know bitwise operations?

Nope.

Servine wrote:

SeptimusHeap wrote:

G0D_M0D3 wrote:

Sorry if this seems spammy, but is the block library dead?

I remember you as a dev, am I right? Or was that a mod, or website...

Anyways, is it dead?

I was a Panther dev.

And yes, Sparks still updates the library.

bobbybee wrote:

Do you know bitwise operations?

Nope.

Hashing isnt the best way. I first thought of that, but there are plent of hash decrypters. Infact, I think you should encrypt it yourself

I got the awesome idea.

If someone manages to get to the project, create a hidden sprite, and put all the decrypting stuff there, that way, it would be almost impossible to decrypt.

Servine, if you hash using a salt, it's near impossible to decrypt if you hide the salt (as I plan to do)

Servine wrote:

SeptimusHeap wrote:

Servine wrote:

Hashing isnt the best way. I first thought of that, but there are plent of hash decrypters. Infact, I think you should encrypt it yourself

I got the awesome idea.

If someone manages to get to the project, create a hidden sprite, and put all the decrypting stuff there, that way, it would be almost impossible to decrypt.

Servine, if you hash using a salt, it's near impossible to decrypt if you hide the salt (as I plan to do)

Well just saying. Its much easier to just encrypt it yourself.

Bobby? nxIII? Can someone help me?

@rookwood101
Thanks for clearing it up for him. Perhaps I'm just not a good explainer.

Sorry about my lack of knowledge in the field, guys. Could anyone explain it in terms that I would understand? I have very little knowledge in the field of data storage and the like. I really only understand the salt part.

SeptimusHeap wrote:

Say user Steve makes an account on my program with inputs:
Username: "Steven6"
Password: "Ilovefido"

My program will create a random salt, for Steve it's "ug78al". How would I hash "Ilovefido" in Scratch using the salt "ug78al"? I know how to place the salt in the final product so that it can be accessed by my client while looking innocent, but how exactly do I hash the original password with the salt?

Normally, you combine the password with the salt and then pass them together to the hashing algorithm. For example, in Python:

>>> from hashlib import md5
>>> password = "Ilovefido"
>>> salt = "ug78al"
>>> md5(password + salt).hexdigest()
'fea0f1f6fede90bd0a925b4194deac11'

For the hash to be useful, you need to have the salt as well (I assume you know this already; but for example: you might store the hash inside a PHP file that checks the user's password against a database. The password + salt is hashed, and the hash is stored in the database, not the plaintext password. If an attacker finds out the salt, then brute-forcing the hashes becomes much easier.)

The hard part in Scratch is the hashing function itself, such as MD5. From what I understand, you're trying to implement a hashing algorithm inside Scratch, which could be very difficult, unless you mod Scratch (you could create an MD5 block!  )

Bobbybee's letter to binary that he mentioned might be a good start.

Have a look at this — it seems to have a good explanation, and might have some simple hash functions you can use.

Hope some of that helps! 

Here you go! I made a little simple rotating hash algorithm in BYOB, based off the article I found. I'm sure you could do it in normal Scratch, too; it'd just take longer to code. 

Here's the BYOB file, and screenshots of the hashing algorithm and the  xor function. 

(Just to warn you; it is a little slow, and I expect it would be slightly slower still in Scratch, despite it being the "simplest acceptable algorithm", according to that article.)

Hope that helps! 

Last edited by blob8108 (2012-01-16 07:14:24)