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uwwmXzKSP0M7DHBHns3v2CtNZh0TOicb

uwwmXH6KGgVLjpnoWCk9I2A+

uwwmcv7JoND9WE6xwaXdN6fLXaecRPqf+m6WmqE

uwAm5NXph0c9hkFK

are originally:

001bboc@explorer.csc.com

001bocaj@gmail.com

001imdc@fountain.mindlink.net

0020@mail.ru

it was written using delphi. The programmer before me quit but didn't leave any notes/source and part of our process is decrpyting the above so we can remove the emails into a dne.

plz does anyone recognize this?

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1) The output looks like it's Base64 encoded 2) The crypto sucks. Perhaps a stream cipher with key reuse. – CodesInChaos Jan 20 at 16:04
i agree it does look base64 is. – Ari Kooshesh Jan 20 at 16:32
It's base64 with trailing = omitted. – David Schwartz Jan 20 at 19:07
Welcome to Cryptography Stack Exchange. The question you asked is of a type which doesn't really fit our question format here – cryptanalysis of home-brewn schemes. (Also, what has this to do with aes?) – Paŭlo Ebermann♦ Jan 20 at 21:25

closed as too localized by CodesInChaos, David Schwartz, Paŭlo Ebermann♦ Jan 20 at 21:23

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, see the FAQ.

1 Answer

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You have to work on it. First, it clearly looks like base64 with trailing = omitted. So make a table of email addresses to base64 decodes. Look for a correlation between email address length and encrypted data length. See how many starting bytes in common you have in the output compared to how many starting bytes you have in common in the input.

If you get stuck, post a question showing what you have already and where you got stuck. Here are a few of the encrypts converted into hex, which is the form you should use to try to analyze them:

$ echo "uwwmXH6KGgVLjpnoWCk9I2A+" | base64 -d | od -x
0000000 0cbb 5c26 8a7e 051a 8e4b e899 2958 233d
0000020 3e60

$ echo "uwwmcv7JoND9WE6xwaXdN6fLXaecRPqf+m6WmqE=" | base64 -d | od -x
0000000 0cbb 7226 c9fe d0a0 58fd b14e a5c1 37dd
0000020 cba7 a75d 449c 9ffa 6efa 9a96 00a1

$ echo "uwAm5NXph0c9hkFK" | base64 -d | od -x
0000000 00bb e426 e9d5 4787 863d 4a41
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