who can help with the octal number system?

Question

I´ve got a message in letters, kind of confusing, but that someone who sent the message said I should use the Octal Number System to find out what it says... Please help... I have tried so much already... Is it even possible to convert numbers into letters from the octal number system?

Answer 1

I have 10 fingers on my hands, 12 in base 8, X in Roman numbers, 00001010 in binary but they all mean 10. So, there is no problem in what system we choose to use to display or talk about numbers. For the computer its all binary, everything is converted to binary, zero or one.

As said by other answers there are 8 "digits" in the Octal system.
0,1,2,3,4,5,6,7. All other numbers will consist of combinations of these. 8 is 10, 9 is 11, 64 is 100, 65 is 101, etc.
You said the message is in letters. The first question is how many different letters are being used? 8 ? if so, then the letters probably represent one of the 8 digits, if not it gets harder.
If both letters and numbers are being used then maybe it is the hexadecimal system (base 16) and not the Octal system. Hexadecimal uses 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F usually.

Of course if you meant your message was in numbers then shame on you. You'll have to learn how to write what you mean. Why would you want to "convert numbers into letters from the octal" ?

Anyway. Assuming you and your friend are both correct.(The message is in letters and it is a Octal code of some sort.) I'm trying to see how more than 8 letters could represent anything meaningful in Octal.....Nothing obvious occurs to me. Perhaps there are spurious letters inserted that are not part of the message? MzEzRzRzYzzXzMzAzS would be a simple example. But if I chose to use the last 8 letters as the "digits"
then 12345 in octal could be TUVWX or with random spacers:
TABUCDVMWXPP (since only the STUVWXYZ count). I could choose any 8 letters and use the rest as spacers.

Three ways to encode a message are as follows:
1.
each Octal number represents the letter with that position in the alphabet: A is 1 or 01 or 001, B is 2 or 02 or 002, H is 10, or 010, etc. up to Z (32) or so (assuming only upper case letters and no punctuation marks). In my above "end of alphabet" example A would be T or ST or SST, and H would be TS or STS and Z would be VU or SVU.
2.
Each Octal number represents a word. Take "MERRY" this could be in decimal 1305181825 (using two digits for each letter)
converting it to octal would be a real pain when you have to start with the highest power of 8 not greater than that number and so on down to 1. (100 base 10 is 64*1+8*4+4 or 144 base 8) (each power of 8 can be multiplied by 0 to 7 but no more!)
3.
Each letter is converted to its ASCII value. And these values are what is converted to octal. A is 65 B is 66,..., a is 97, b is 98, etc.
65 base 10 is 101 base 8. THere is plenty on the Web about ASCII code so you will be able to figure it out if thats it.

These would all be considered very weak ciphers. Really complicated ones can only be cracked by computers searching for patterns or by someone with a lot of elbow grease and time.
A common strategy to crack toy codes is to find how often a letter (symbol) appears. In English, the most common letter is "E" if I recall the order is etaoinshrdlu. If some letter is occuring often in the code, maybe its an "e".
In octal, we know we need at least two places for 26 letters: 01 - 32 (base 8) but that would leave us 46 (base 8) more not used. what we do is assign some of these to the most common letters to hide their frequency of occurance and it gets much harder to crack. So, for every strategy there is a counter strategy. Good Luck! If you still have problems cracking it you need to post some of the code to give us a better idea of what it looks like.

Answer 2

The octal number system means, that in contrast to the decimal system there are only eight numbers: 0, 1, 2, 3, 4, 5, 6 and 7. Eight is written 10. 100 in the octal system is as much as 64 in the decimal system. If you take the octal number 31, for instance, (three times eight plus one), you get a decimal 25.
I'm sorry, but I don't see how letters can come into it. If there are only eight different letters, you may have to substitute each letter by a number between 0 and 7. This first solution you would have to rewrite in the decimal system and there try with substituting numbers by letters to find the real message.
That can be very tricky! Good luck!

Answer 3

The base 16 system uses the numbers 0 to 9 and the letters A to F because, being base 16, it needs 16 digits. But the octal system, being base 8, needs only the digits 0 to 7. So in the octal system, the numbers 0 to 7 are the same as in base 10. 8 is written 10, 9 is 11, 17 is 21 (2 times 8^1 plus 1). 64 is 100 (1 times 8^2 plus 0 times 8^1 plus 0). The octal number 6314 is, in our familiar base 10, 6 times 8^3= 6times 512=3072, plus 3 times 8^2= 3times 64=192, plus 1 times 8^1=8, plus 4; total 3276. So unlike base 16, or any other systems with a base greater than 10, you don't need to worry about letters. Let's convert the other way, base 10 to octal. In octal, our ordinary base 10 number 765 is 1 times 8^3, which is 512,plus remainder 243. 243 is 3 times 8^2, which is 192 plus remainder 51. 51 is 6 times 8 plus remainder 3. So 765 is, in octal, 1363. As for your message, my guess at how to decode it (no guarantees though), is, convert it into base 10 numbers and maybe each number represents a letter of the alphabet, like 1=A, 2=B and so on.