Encryption

Decode

Encryption is scrambling data in such a way that only someone with the secret code or decryption key can read it.

Encryption has been around for thousands of years in various forms. For example, in Ancient Greece the story goes, a general by the name of Histiaeus wanted to send a secret message back to his city. So, he had a slaves’ head shaven and the message written on the slaves’ scalp. Soon his hair grew back enough to hide the message and he was sent off to the city. When the slave arrived, the city official knew the secret ‘key’ i.e. shave the slaves head to reveal the message.

Today, encryption is far more sophisticated, but it serves the same purpose – to pass a secret message from one place to another without anyone else being able to read it.

By their very nature mobile devices such as laptops, smartphones and tablets have a high risk of loss or theft. Encryption of the data contained on the device can provide an assurance that, if this happens, the risk of unauthorised or unlawful access is significantly minimised.  Encrypting emails prevents unauthorised people from accessing them. It is also good practice to use encrypted communication when transmitting any data over a wireless communication network (eg Wi-Fi) or when the data will pass through an untrusted network.

This short youtube video by Austin Evans explains why encryption matters https://www.youtube.com/watch?v=6M5seN3u6mo&feature=youtu.be

There are many different apps and browser extensions available to help with encrypting emails and attachments.

The need to conceal the meaning of important messages has existed for thousands of years. Over time, people have found increasingly complex ways of encoding their messages as the simpler ways are decoded with greater ease. Codes and ciphers (cyphers) are not the same. A code is where each word in a message is replaced with a code word or symbol, whereas a cipher (cypher) is where each letter in a message is replaced with a cipher (cypher) letter or symbol.

Some ciphers (cyphers) work by simply realigning the alphabet (for example, A is represented by F, B is represented by G, and so forth). However, almost all serious ciphers (cyphers) use both a key (a variable that is combined in some way with the unencrypted text) and an algorithm (a formula for combining the key with the text) known as cryptography. A block cipher (cypher) is one that breaks a message up into chunks and combines a key with each chunk (for example, 64-bits of text). A stream cipher (cypher) is one that applies a key to each bit, one at a time. Most modern ciphers (cyphers) are block ciphers (cyphers).

Ciphertext is encrypted text. Plaintext is what you have before encryption, and ciphertext is the encrypted result. The term cipher (cypher) is sometimes used as a synonym for ciphertext, but it more properly means the method of encryption rather than the result.

To learn more about ciphers (cyphers), go to mozilla’s CODEMOJI and compose a fun message to send to your friends. https://codemoji.org/#/welcome

Next: Passwords