Computers use a variety of numbering and character encoding formats for processing efficiency (not for confidentiality). For cyber competitions, student must be able to convert a computer number format or text (ASCII) encoding format to the other equivalent numeric or text formats. Use a conversion tool (see links below).
Binary, octal, decimal and hexidecimal are popular positional numeric systems that can be used for arithmetic operations. Base64 is a binary-to-text encoding scheme that translate data into an ASCII string format using a radix-64 representation. ASCII is a character encoding standard for electronic communication that assigns a numeric value to 256 text and special characters. Unicode is a expansion to ASCII with support for over 1.4m characters.
Numbering and Encoding Systems:
Below are the most popular numbering and character encoding schemes use :
- Binary – Base2 (characters = 0,1) : core base for computer processing
- Octal – Base 8 (characters = 0,1,2,3,4,5,6,7)
- Decimal – Base 10 (characters = 0,1,2,3,4,5,6,7,8,9)
- Hexidecimal – Base 16 (characters = 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F)
- ASCII – Text characters that have a corresponding numeric value
- Unicode – International standards based on a superset of ASCII plus characters from all written languages.
- Base32 – binary-to-text encoding that produces an ASCII string format by translating the data using 32 characters (UPPER CASE ALPHA + numeric) . Either three Alpha (XYZ) or three numeric (0,1, 3) are not used based on the variation.
- Base64 – binary-to-text encoding that produces an ASCII string format by translating the data using 64 character representation (upper and lower case alpha, numeric, ‘+’, and ‘/’ symbols…. with the ‘=’ as no value padding)
- Other – A variety of additional bases may used depending upon the circumstances
- Number Converter ( Binary, Octal, Decimal, Hex)
- Octal to ASCII (Text)
- Hex to ASCII (text)
- Binary to Text
- ASCII Text to Numbers (Hex, Decimal, Binary)
- Base64 (Text, Hex, Video, Audio, etc. )
- Base2-36 – Base2 to Base36 Converter
- Unicode Converter
- CyberChef – The Cyber Swiss Army Knife to detect and convert encoding formats
- Number Systems Introduction – Decimal, Binary, Octal & Hexadecimal (YouTube 10:56 mins)
- What is Base64? (YouTube 3:41 mins)
- What is ASCII? (YouTube 2:16 mins)
- Unicode (Youtube 3:01 mins)
- Encoding Schemes and Number System (18 pgs)
- Binary Math – N10-008 CompTIA Network+ : 1.4 (Youtube 7:48)