White Hat Institute

“Defend the Web” write-up (Crypt 1 / Crypt)

“Defend the Web” write-up (Crypt 1 / Crypt — reverse encryption)

The reverse cipher encrypts a message by printing it in reverse order. So “Hello world!” becomes “!dlrow olleH.” Decryption is as simple as reversing the reversed message to obtain the original message. The steps for encryption and decryption are the same.

This is a very simple challenge. In this example, a reverse text is already given, so we need to decrypt it to reveal the password.

Defend the Web - Crypt1-1

Copy the reverse encrypted text. Open up your browser and Google search for “decrypt reverse text”.

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Click on any available link and paste the text to decrypt.

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We found the password. Copy and use it on the login page to pass the challenge.

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The reverse cipher is an extremely vulnerable cipher. You can tell it’s in reverse order merely by looking at the ciphertext.

“.syas ti tahw tuo erugif llits ylbaborp nac uoy ,detpyrcne si siht hguoht neve ,elpmaxe roF”

In a nutshell, just stay away from this type of implementation in any kind of security measurements.