Base58
en.wikipedia.org
Base58
1–10 of 44 posts
Re: Base58
#2I love interesting representations of binary data, base 58 included, but this article is so scant on details. I'm sure someone could even add a brief overview of the algorithm and samples and it's limitations and idiosyncrasies, such as how it handles things like padding etc.
Re: Base58
#3There are many dimensions to utility.
Re: Base58
#4Why base-58 instead of standard base-64 encoding?
- Don't want 0OIl characters that look the same in some fonts and could be used to create visually identical looking data.
- A string with non-alphanumeric characters is not as easily accepted as input.
- E-mail usually won't line-break if there's no punctuation to break at.
- Double-clicking selects the whole string as one word if it's all alphanumeric.
Re: Base58
#5I'm actually using base 58 to encode numbers for the gopher URL shortner with the Ripple alphabet. It works as advertised, and is great for an old protocol like this.
gopher://fld.gp/1/gopher/shorten (shortened URL example: gopher://fld.gp/1j/r or http://fld.gp/1j/r )
Re: Base58
#6Reminds me of Crockford's https://www.crockford.com/wrmg/base32.html
Re: Base58
#7I love interesting representations of binary data, base 58 included, but this article is so scant on details. I'm sure someone could even add a brief overview of the algorithm and samples and it's limitations and idiosyncrasies, such as how it handles things like padding etc.
I think the article is good as is, because base58 is actually pretty dissimilar to most binary-to-text encodings. Surprisingly many encodings are just base 2^k (16, 32, 64 and 128 [1]), some have converged to base 85 (because 85^5 / 2^32 ~= 1.03, i.e. just enough to represent 4 octets in 5 units). This is because binary-to-text encodings are not expected to use costly bigint operations for an arbitrary-length payload. Base36 and base58 are the only common exceptions, and for this reason I actually think that they should be termed "bigint-to-text" encodings.
Given that base58 is actually just a big number with translated digits, the list of alphabets (actually, digits) is almost enough to decode base58 encodings. There is always an exception, of course: Bitcoin base58 calculates a minimal length from the original payload length so that it has to be "zero"-padded with one (which is the first alphabet, thus acts as a digit zero) [2]. This preserves the original payload length, but is still quadratically expensive and should be used for a reasonably short, known-length data like hashes.
[1] This is actually not normally viable as a binary-to-text encoding, but base122 (http://blog.kevinalbs.com/base122) does use this to exploit UTF-8 encoding.
[2] https://en.bitcoin.it/wiki/Base58Check_encoding (note that I've used a significantly simpler explanation here, the gist is same however)
Re: Base58
#8I love interesting representations of binary data, base 58 included, but this article is so scant on details. I'm sure someone could even add a brief overview of the algorithm and samples and it's limitations and idiosyncrasies, such as how it handles things like padding etc.
The best-kept secret Wikipedia is the references section. First reference probably answers all your questions.
For those of you still in school, this is also how you "get around" the "Don't use Wikipedia" restriction on your school reports. You go to the Wikipedia article for whatever it is you're writing about, ignore it entirely and scroll down to the References, and go to town on those. 10 seconds of "research" and you've almost certainly got enough primary sources lined up to finish your report unless this is a thesis-level job. I scare-quote "get around" because this isn't even really "cheating", unless you're doing the assignment where you're explicitly instructed to use the library lookup system, in which case of course it is.
Re: Base58
#9Not to be confused with Base85.
https://en.wikipedia.org/wiki/Ascii85
(used with various alphabets for denser binary encoding in PDF, git binary patches, and the scene files of the Arnold renderer).
Re: Base58
#10Neat. Side note, there's another project called HashIds with many language implementations for encoding integers (or array of integers) into simple alphanumeric strings, and decoding back again.