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by kobeya 3491 days ago
I'm pretty sure that Bitcoin has dealt with this issue for its base58 encoding. It might be worth checking if their algorithm is generalizable to other radix sizes.
2 comments
deckar01 3491 days ago
Check out digit-array if you are interested in the generalized algorithm. The source code is commented with formal math notation for the operations.

https://github.com/deckar01/digit-array/blob/master/README.m...

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CiPHPerCoder 3491 days ago
This doesn't appear to address the problem. At all.

https://paragonie.com/blog/2016/06/constant-time-encoding-bo...

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deckar01 3491 days ago
I misread your original comment. Nothing I posted is related to constant time encoding. I apologize for the confusion.
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CiPHPerCoder 3491 days ago
It's OK. I just want to be clear that my objection to base-122 is the same as my objection to base-N where N != 2^m for some integer m.
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CiPHPerCoder 3491 days ago
No, it hasn't. I sent a pull request that attempts to solve this problem for a C# implementation of Base58Check, but there's no way for me to reliably guarantee that data isn't leaking from the divison.

https://github.com/adamcaudill/Base58Check/pull/3

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