Cryptography is the science of developing methods to disguise data – for example, promoting each letter by 3 places so that “Tuesday” becomes “WXHVGDB”. In todays world, cryptography is the science of transforming data through complex mathematics. This process is known as encryption, and transforming it back again is decryption. Here’s 8 simple facts you should understand about cryptographic technology.
1. CIA – an acronym for the basic requirements of useful data encryption:
* Confidentiality – encrypted data cannot be read.
* Integrity – the encrypted data cannot be altered.
* Availability – the system can quickly decrypt the data when needed.
2. Multiple Layers
A file or email may pass through multiple computers or applications before it’s finally archived or deleted. At each point in the process, it could be subject to hacking. In a secure system, it would receive another cryptographic layer at each point. This is called defense in depth.
3. Strong Cryptography
A simple cipher like the one above might baffle your mother, but a cryptanalysis program would see right through it. Strong cryptographic technology uses highly sophisticated mathematical algorithms to code your data so that even well-funded spies can’t read it.
Today’s algorithms rely on a “key” to encrypt data. A message can only be decrypted with the decryption key. There can be a different decryption key, but in many cases they are the same key.
5. What is a key?
A key could be any alphanumeric string – but in today’s technology, it’s a random series of bits. That particular key is used in the algorithm, so that a different string would produce a different result. Only the correct key will decrypt the data.
6. Symmetric Key
The same key is used for encryption or decryption, or else the decryption key could be derived from the encryption key. However, this requires some secure means of sharing the key.
7. Asymmetric Key
This uses two keys: a public key for encryption and a private key for decryption. The public key is made available so that anyone can encrypt data, but only a person already having the private key can decrypt the data; the private key is never sent.
8. Hash Function
This takes a file of any length as input to produce a fixed-length result, say 100 bits. Any change to the original data would produce a different hash value, indicating the file was corrupted or tampered with.
Some might argue that the demand for encryption goes against the greater public good, but computers without encryption mean some hacker on the other side of the planet could steal your identity, take your money, and ruin your life. Cryptographic technology is more important than ever.