How does using Only Typable Characters affect the Number of Possibilities?
A 128 bit password has 128/8 characters, or 16 characters. If each of these 16 characters can be selected from the 256 available (28), then the number of possibilities is: 25616. Or (28)16. Or 2128 Or: 340,282,366,920,939,000,000,000,000,000,000,000,000 possibilities (approximately 3×1038) On the other hand, if only the 96 typable characters are used, the number of possibilities is: 9616 Or 52,040,292,466,647,300,000,000,000,000,000 different possibilities. The equivalent of this in bits is: log(possibilities)/log(2) Or approximately: 105.3594 bits (The decimal part makes a big difference here). So, if only typable characters are used 128 bit encryption becomes a little more than 105 bit encryption. Similarly, if only the letters and the numbers (62 possible characters) were used then the equivalent in bits would be: 95.2671 bits. (The number of possibilities is about 5×1028) This has reduced the possibilities by a factor of 7,137,932,110 (about 7×109), making it thousands of millions
