Encryption Presentation Jamie Roberts

Encryption Defined: n The process of converting messages, information, or data into a form unreadable by anyone except the intended recipient.

Cryptography, Cryptanalysis, and Cryptology n Cryptography is the art or science of secret writing n Cryptanalysis is the practice of defeating attempts to hide information. n Cryptology includes both cryptography and cryptanalysis. n Most forms of cryptography in use rely on computers, simply because human-based code is too easy for a computer to crack.

Plaintext and Ciphertext n Plaintext is the original information that is to be hidden n Ciphertext is the hidden information. n Encryption is any procedure to convert plaintext into ciphertext.

Decryption n The process of reproducing data from an encoded message based on a known code or cipher. n The code is decrypted using a list, table, or key. n Decryption is any procedure to convert ciphertext to plaintext.

History n Encryption has been around at least four thousand years n The earliest use of encryption was circa 1900B.C. when an Egyptian scribe substituted unusual symbols for standard hieroglyphs in an inscription

The Enigma Machine n Between the Enigma became the cryptographic workhorse for Nazi Germany. n It was broken by a Polish mathematician, M. Rejewski, based only on captured ciphertext and one list of three months worth of daily keys obtained through a spy. Continued breaks were obtained by Alan Turing, Gordon Welchman and others in England.

How data is encrypted n Basically encryption is a process of substitution. n An alternative value, known as a token or token character, is substituted for designated elements of a message or other data. n For example, the letter r might be replaced by the letter m.

n Anything can be used as a token character even a space can replace a numeral or letter. n Often during encoding each and every character is replaced BUT not always n Also, substitution isn’t always on a character by character basis.

n One character can represent an entire word or group of bytes. n And just to confuse you even more, a word or group of bytes may represent one letter or numeral. n Most encryption schemes vary the pattern of substitution enough so there is no recognizable pattern.

The Code or Cipher n The type of substitution made (one character for many, many characters for one, repeating or non-repeating patterns) and/or the pattern of substitutions is referred to as the code or cipher.

Symmetric Key Encryption n In this type of encryption, each computer has a secret key (code) that it can use to encrypt a packet of information before it is sent over the network to another computer.

Public Key Encryption n This type of encryption uses a combination of a private and public key. n The private key is known only to your computer, while the public key is given by your computer to any computer that wants to communicate securely with it.

The Importance of Encryption n With the advancement of computers and interconnectivity, the US governmental institutions and industries are subject to cyber attacks, intrusion, and espionage. n Now that commercial trading on the net is a reality, one of the main targets of data encryption is credit card numbers.

n Most importantly, there is a whole lot of information that we don’t want other people to see, such as: n credit-card information, social security numbers, private correspondence, personal details, sensitive company information, and bank account information.

Ethical Issues Concerning Protection of Data n The debate over encryption revolves around the permanent conflict between industrial competitiveness and personal privacy and the interests of national security and law enforcement. n There is often mistrust felt by citizens and corporations against state mandates to cryptanalyze encrypted information

Security and Freedom through Encryption (SAFE) Act n The SAFE Act ensures that all Americans use escrow by prohibiting the domestic manufacture, sale and importation of any encryption product unless the government is given immediate access to the plaintext of communications and stored files without the knowledge of the user. It also requires that any encryption product manufactured or sold in interstate commerce, or imported into the U.S., shall include features that permit immediate access( pursuant to appropriate judicial process) to the plaintext of communications or electronic information encrypted by such product without the knowledge or cooperation of the person using such product.

Markey-White Amendment n Basically says that domestic encryption cannot be regulated by the Federal government or by the States. n Also creates stiffer penalties for person’s who use encryption to commit or hide their crimes.

Applications for Encryption n File storage: you may find encrypting files a practical way to protect your information. n practical if you fear others may read your n Data transmission: if you plan to send sensitive data files to others or to yourself for online storage, you will probably want to encrypt those files

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