3ncod1ng @ Dec0di2g

This article is about encoding and decoding, and how it works (VPN, Secret codes & other encoding related things), I hope you enjoy reading through.

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Hard drives can be encoded so that to unlock them, you must type in the password that I am going to refer to as a “Key”, and the keys are the sequence to decode the jumbled digits.

MFM (Modified Frequency Modulation) is a RLL (Run-Length Limited) coding scheme, it was introduced to hard drives in 1970, then, 6 years later (1976) it was introduced to floppy disks. MFM is a modification of FM encoding, and is used less for storage encoding and more for magnetic field decryption.

Disk encryption is less the encoding type and is more the encryption type, and is used for the actual security side. It works by using the binary digits of the Key and, depending on the encryptor, it will modify the bits in the hard drive in a certain controlled way, for example, selectively swapping certain bits.

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Sometimes, you may want to hide the data that you are sending and receiving, that can be achieved via Proxies and VPNs.

Proxies and VPNs are pretty much the same, apart from a few small differences, but the encryption / decryption is the same. If you send your decryption key, then someone could use it to decrypt the data going to and from the host and the computer, and if you don’t send it, then the host will have no idea what your request is and vice versa.

To fix this problem, we will generate a random number ranging from 4 to 64+ digits (depending on the encryption amount needed), and that will be our encryption key. Then, we will encrypt that key in a certain way, that with two or more uses, that the data will be decrypted. Then you will keep the decryption key and send the server your encryption key, so whoever gets the key will only be able to encrypt the data, and not be able to decrypt it. Then, using the encrypting key, you will encrypt the decrypting key and send that to the server, then you can encrypt and decrypt without the risk of anyone getting in. The problem is, that if someone gets the encrypting key, then they will be able to change it into the decrypting key after 20-30 minutes minimum, so to solve this, the server and computer will change the key every 10-20 minutes.

En1gm4 Mach1n3

The Enigma machine was used by German soldiers in WWII to send secret messages, the code generated by the machine was almost random, showing different letters for the same letters and vice versa, it was thought to be uncrackable. To crack this code, you would rotate the spindles to the start of the particular number the code was typed on, and it will give you the code. The number of possible combinations was roughly equal to 158,962,555,217,826,360,000 combinations.

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Wikipedia: MFM (Modified Frequency Modification), Disk Encryption

Numberphile