Across
- 2. a method of compressing text files
- 5. message data before it is encrypted.
- 6. a type of transposition cipher that encodes the message by placing it into a grid.
- 7. any number that can be expressed as a fraction or ratio of integers.
- 9. the science of designing cipher systems.
- 12. a method of working with signed binary values.
- 19. width × height of an image or number of pixels per inch.
- 26. the number of bits or bytes allocated to represent the colour of a pixel in a bit-mapped graphic.
- 28. the process of reducing the size of a file
- 29. in cryptography it is the data that is used to encrypt and decrypt the data.
- 30. the grouping together of bits or bytes to form larger blocks of measurement, e.g. GB, MB
- 32. a positive whole number including zero
- 37. red, green and blue filters that light passes through in order to create all other colours.
- 38. a method of encryption where one character is substituted for another to create ciphertext
- 40. the difference between the actual number and the nearest representable value.
- 42. a method of checking binary codes by counting the number of 0a and 1s in the code
- 43. reducing the number of digits used to represent a number while maintaining a value that is approximately equivalent
- 47. the ‘power of’ part of a number indicating how far a binary point should be shifted left or right.
- 48. a locally unique 32-character code that identifies a device on a wireless network
- 49. message data after it has been encrypted.
- 52. a method of encryption where the characters are rearranged to form an anagram.
- 54. using an algorithm and a key to convert message data into a form that is not understandable without that key.
- 55. a number that cannot be represented as a fraction or ratio as the decimal form will contain infinite repeating values
- 56. where the decimal/binary point can move within a number.
- 58. used to store a 0 or 1 depending on the result of binary addition
- 59. in cryptography it is the study of how often different letters or phrases are used.
- 60. the maximum number of significant digits that can be represented.
- 61. a process for adjusting numbers onto a common scale.
Down
- 1. a binary representation of a particular letter, number or special character.
- 3. using an algorithm and a key to convert encrypted message data into its plain text equivalent.
- 4. the process of cutting off a number after a certain number of characters or decimal places
- 8. the significant digits that make up a number
- 10. an image made up of objects and coordinates
- 11. a real number represented by a sign, some significant digits (the mantissa) and a power of 2 (the exponent).
- 13. a substitution cipher where one character of plaintext is substituted for another, which becomes the ciphertext
- 14. data that has been encrypted.
- 15. a type of transposition cipher that encodes the message by splitting it over rows
- 16. a method of compressing data by eliminating repeated data
- 17. any positive or negative number with or without a fractional part
- 18. the result of a calculation is too large to be represented using the available number of bits.
- 20. a method of trying to find the plain text from the cipher text without the decryption key.
- 21. a method of checking for errors by producing the same data several times and checking it is the same each time.
- 22. where the decimal/binary point is fixed within a number
- 23. an image made up of individual pixels.
- 24. a number used to identify position relative to other numbers.
- 25. an algorithm that encrypts and decrypts data, also known as code.
- 27. the absolute error divided by the actual numbers.
- 31. a picture element – the smallest unit that combined with other pixels makes up a picture, for example, a digital photograph.
- 33. when a number is too large to be represented with the number of bits allocated.
- 34. a method of encryption that uses a onetime pad (key) to create ciphertext that is mathematically impossible to decrypt without the key.
- 35. a digit added to the end of binary data to check the data is accurate
- 36. binary that represents positive numbers only.
- 39. a standard binary coding system that has superseded ASCII.
- 40. a standard binary coding system for characters and numbers.
- 41. a key that is only used once to encrypt and decrypt a message and is then discarded.
- 44. any whole positive or negative number including zero
- 45. when a number is too small to be represented with the number of bits allocated.
- 46. the number of digits available within a particular number system, e.g. base 10 for decimal, base 2 for binary
- 50. a single binary digit from a binary number – either a zero or a one
- 51. a group of bits, typically 8, used to represent a single character
- 53. binary with a positive or negative sign.
- 57. how accurate a number is