Network Encryption

Vince Ceccarelli

Group 7

TC 200

What is Encryption?

• Encryption – a process that hides the content of a message in such a way that it can be revealed through a decryption process

• Encryption and decryption are processes of Cryptography

• Cryptography - study of techniques using secret writing as codes or ciphers

How is it done?

• The cryptography process uses encryption/decryption algorithms

• The algorithms use a key - a long sequence of bits (1s, 0s)

• The key is used to alter the original message mathematically to create a new encrypted/decrypted message

Keys

• The keys provide the necessary means of protection

• They must be kept secret or anyone with knowledge of them would be able to crack the decryption process with the right algorithm

• In some cases two keys are used, one for encryption and one for decryption

• This can make the encryption key public and the decryption key private

Keys and Bits

• Keys are determined by the amount of bits they have (amount of numbers)

• All the possibilities of a 2-bit key:

00,01,10,11

• A 3-bit key has 8 possible values

• Possible values formula – 2^n (n being the number of bits)– 40-bit key has 1.099511628E12(2^40)

Types of Encryption Algorithms

• RSA

• DES/3DES

• BLOWFISH

• IDEA

• SEAL

• RC4

RSA

• Created in 1977 by Ron Rivest, Adi Shamir, and Len Adleman

• Uses public and private key

• Starts with 2 large prime numbers

• Goes through long math process

• Results in a public and private key

DES/3DES

• Data Encryption Standard• Developed by U.S. Government in 1977• Uses a 56-bit key• Used in ATMs • 3DES is the same thing except it encrypts

the data 3 times and uses a different key for at least one of the passes

• This creates a cumulative key size of 112-168 bits

BLOWFISH

• Designed by Bruce Schneider in 1993

• Uses keys from 32 to 448 bits

• It was a fast, free alternative to encryption algorithms when it came out

IDEA

• Developed by Dr. X. Lai and Prof. J. Massey in Switzerland in early 1900s

• Replaced the DES standard

• Uses a 128 bit key

• Said to be impossible to break by checking every key

• No other means of attack is known

SEAL

• Software-optimized Encryption Algorithm

• Designed by Rogaway and Coppersmith in 1993

• Uses a 160 bit key

• Is a Stream-Cipher – data is encrypted continuously as opposed to Block Ciphers (DES, BLOWFISH, and IDEA)

RC4

• Invented by Ron Rivest, Co-Producer of RSA

• Used in Lotus Notes and Netscape

• Uses up to a 2048-bit key

• Useful in situations in which a new key can be used for each message

SOURCES

• http://compnetworking.about.com/od/networksecurityprivacy/l/aa011303a.htm

• http://www.mycrypto.net/encryption/crypto_algorithms.html• http://www.cohn-family.com/images/cert-rsa-encryption.jpg• http://gnrt.terena.org/gfx/book/ProtectingUsers/public-key-

encryption_smaller.gif• http://gnrt.terena.org/gfx/book/ProtectingUsers/single-key-

encryption_smaller.gif• http://www.skilldrive.com/book/DOTNET%20in

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