Codes and Cryptography

modulo operation

The ________ (abbreviated "mod, "or "% "in many programming languages) is the remainder when dividing.

Channel

________- Vehicle through which communication travels.

Lossless Compression

________- No data lost when file is reduced.

Cryptography

________- the process of making and using codes to secure transmission of information.

CODECs

________ are algorithms, mathematical formulas used to compress and decompress files.

Decryption

________- The conversion of encrypted data into its original form.

Feedback

________- Reply or response to the message.

Encryption

________- converting original message into a form unreadable by unauthorized individual.

Digits

Check ________- Check ________ or a Check Sum is used to verify errors on identification numbers.

Lossy Compression

________- Small losses in data is tolerable.

Communication technology

________- the transfer of messages (information) among people and /or machines through the use of technology such as telephone, radio, television, and internet.

Error

________- Is a condition when the transmitted information is not the same as the information sent.

Universal Product Code

________- UPC- Consists of 12 digits; the first 11 characters specify the source of the item and the product number.

Parity Check

________- One extra bit is sent along with the original data bits.

Communication technology

the transfer of messages (information) among people and/or machines through the use of technology such as telephone, radio, television, and internet

Cryptography

the process of making and using codes to secure transmission of information

Encryption

converting original message into a form unreadable by unauthorized individual

Decryption

The conversion of encrypted data into its original form

Modular Arithmetic

a = b (mod n) & a ≡ b mod n; a,b ∈ ℤ, n ∈ ℕ, 𝑛 > 1

Linear Congruence Definition 1

If a and b have the same remainders when divided by n

Linear Congruence Definition 2

If n divides a-b, which means that a-b is an integer multiple of n

Gen form

ax ≡ b mod n

Source

Sender of the message

Receiver

Recipient of the message

Encoding

The process of turning thoughts into communication

Decoding

The process of turning communication into thoughts

Feedback

Reply or response to the message

Message

Content of communication

Channel

Vehicle through which communication travels

Examples

Hieroglyphics, Roman Numerals, Hindu Arabic Numerals, Musical Scores, Genetic Codes, DNA, zip codes, Identification numbers for people, accounts or documents, bar codes

Lossless Compression

No data lost when file is reduced (Examples: WinZip, 7z, GIF & PNG)

Lossy Compression

Small losses in data is tolerable (Examples: JPEG, MPEG)

Error

Is a condition when the transmitted information is not the same as the information sent

Error correction

when it detects an error it tries to put data back to how it should have been

Error control

the general term for correction and error detection systems

Parity Check

One extra bit is sent along with the original data bits

Check Digits

Check digit or a Check Sum is used to verify errors on identification numbers

Bar Codes

Code printed on retail product packaging to aid in identifying a particular item/product (Examples: UPC-A, EAN-13,ISBN)

Universal Product Code -UPC

Consists of 12 digits; the first 11 characters specify the source of the item and the product number

Uses modular arithmetic

f(p) = (m + 3 mod 26)