dmg

@Otaia Alternatively, he was born on the 15 January.

@Otaia MLK, Jr. got his Bachelor of Divinity in 1951.

Since we're getting rolling Nelson Mandela was in office until 14 June 1999, making the 13 his last day.

@SteveJessop Within a class, there is an ordering. And that is it. I don't know why you are trying to put real numbers in the problem, as each sequence maps to an integer, not a real number.

@DanielWagner Yeah, you are right. Fixed.

@SteveJessop Take a look at the end of the answer.

@DanielWagner Take a look at the end of the answer.

@SteveJessop The possible sequences have a well defined order.

@SteveJessop Assuming dwarves can work with infinite data, they technically can choose a member of the infinite set of sequences within a class.

@DanielWagner You realize, that giving a full example, when talking about infinity is not quite possible?

@DanielWagner You are right. Corrected in the answer. Anyhow, a possible partition will be through a prefix of fixed size. The representative, will be the one which starts with all "red"s.

@CarlWitthoft Why in the same way a dwarven population reaches infinite numbers. Guess they've had a lot of time to evolve their brains into. They've also developed infinite sewing machines.

@AE As differences between classes are of infinite length, there is an infinite number of possible distances, which means there is an infinite number of classes.

@AE :D I must appreciate your infinity profile pic, though. Careful when working with infinity. A lot of mathematicians have gone mad after studying infinity.

@AE Exactly. By definition this is the main constraint when building the classes.

@AE It is not possible by definition. Since each sequence belongs to a single class and each class contains only sequences that differ from the representative by a finite number of elements. If X differs from Y and Z by a finite number of elements, then Y and Z differ from each other by a finite number of elements, thus Y and Z are in the same class.

@AE There is one representative for a class. Remember, the members of each class differ from the representative by only a finite number of elements and each possible sequence belongs to a single class. The dwarves deduce the class because each one sees an infinite part of the infinite sequence. The only thing, a dwarf cannot do on their own is to deduce the difference between the current sequence and the representative.

@EFrog "brbr" will be in another "class". Notice that sequences in the class differ by a finite number of elements. That is, you can count the differences and the first dwarf does exactly that. All dwarves can deduce the sequence and the representative of the sequence. Infinite mismatches within a class are not allowed by definition.

same. see you later.

@BmyGuest Your circular puzzle is actually an example of what a great cipher puzzle should be

Still, the easiest way to battle the brute-forcing is by using way too little text

:D

I see, that makes more sense now

Usually when I say "encryption" I'm talking about industry standard encryption algorithms :D

What I meant was. Personally, I associate ciphers with puzzles. Ciphers can be solved manually with a little (or a lot of) thought

Hmm, perhaps I chose bad words for what I meant

I think, that we should try and differentiate between ciphers and encryption here

I depends on the viewer I guess. A little cipher text, with reasonable hints to the cipher and key is OK with me

:D

Ah, yes "too lil' text"

Most ciphers (not encryptions, but ciphers), usually require a page of text if they are not Ceasar or something that simple

This can be usually battled with short ciphertext

:D

Personally, I hate decryption puzzles, when there is no obvious cipher

I see, but the process of checking an idea will be very hard to do manually

But also, if there is no hint to the key for the industry-standard encryption, average puzzle-solvers won't be able to get to the second part

I think that SHA, RSA or whatever, is more computationally expensive than a dictionary lookup

but what if someone brute-forces, sees "Oh, there is an English word here" and continues from there

I see

and in your example "NOW USE THE NUMBER BEFORE TWELVE AS KEY FOR SUBSTITUTE" is perfectly understandable for average language processing tools

and the second flaw is that language processing has gone a long way for the last years

:D

for example, the NSA thinks you are terrorist, they process your history pseudo-manually

the first flaw is that, one can store the result of the first decryption and only process it if it is needed

as for your example in the edit, I can see two flaws

if we add this to any other encryption standard, people will know that "hey, after I brute-force this first step, I should run it through the Ceasar brute-forcer"

what I meant was

and all that

how an encryption algorithm works

it is technically known