sipa

import sys
import re
import ipaddress

# This program loads AS mapping entries from stdin in the form "[IP]/[bits] AS[num]", where IP is an IPv4
# or IPv6 address, bits is an integer between 0 and 32 (for IPv4) or 128 (for IPv6), and num is an integer
# between 1 and 16777215.

def Parse(entries):
    for line in sys.stdin:

sipa

Moved to https://github.com/sipa/writeups/tree/main/minimizing-golomb-filters

sipa

1 state:
Output rate: 0.25
N0 (pos 0)
S0: 0=S1 1=S2 [0.5]
S1: 0=S0 1=0,S0 [0.25]
S2: 0=1,S0 1=S0 [0.25]

2 states:
Output rate: 0.375
N0 (pos 0)

sipa

Keybase proof

I hereby claim:

• I am sipa on github.
• I am pwuille (https://keybase.io/pwuille) on keybase.
• I have a public key whose fingerprint is 133E AC17 9436 F14A 5CF1 B794 860F EB80 4E66 9320

To claim this, I am signing this object:

sipa

The algorithm that used to be described here is broken.

A better alternative is described here: https://github.com/sipa/writeups/tree/main/elligator-square-for-bn

sipa

Chances of not detecting an error in a Bech32 string. Lengths exclude the separator character '1'. Chances are multiples of 1 in 2^30.

 Len   1 Error             2 Errors            3 Errors            4 Errors            5 Errors            6 Errors            7 Errors           8 Errors
   1   0.000000000000000                    
   2   0.000000000000000   0.000000000000000
   3   0.000000000000000   0.000000000000000   0.000000000000000
   4   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000
   5   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000
   6   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000
   7   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000   0.000000000000000   1.209844924575586

sipa

• Zero-length integers are accepted (with value 0), 8.3.1 says this is not allowed.
• Expected-to-be-unsigned integers are parsed as if they weren't two's complement, violating 8.3.3.
• Integers with excessive padding are accepted, violating 8.3.2.
• Primitive values with indefinite length are accepted, when they are inside a constructed value with known length, violating 8.3.2.a. End-of-contents octets are not supported in this case, violating 8.1.5.
• Lengths of constructed values are ignored in several cases.
• Garbage inside sequences is accepted.
• Garbage at the end is accepted.
• Data types that are required to be primitive can be encoded as constructed instead, in which case the concatenation of all primitive values inside is used (ignoring their data types), violating for example 8.3.1.
• 127-byte long length descriptors are accepted (ASN.1 allows up to 126 bytes), violating 8.1.3.5.c.
• Older OpenSSL code only accepted length descriptors up to the size of a 'long int' (which is platform dependent),

sipa

Published as BIP 103

sipa

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

Here is a public key of mine, usable for the CoinJoin bounty fund:
0292782efcb08d621c360d055f407c8e75ffbbd06f6b7009c1432ca9eaa6732592
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)

iQGcBAEBCAAGBQJSpLf6AAoJEI9lMlXIeZLgtRkL/3ufWgLyhTKM9T30JqA0a/Xh
5KUMD0csuxTMYraVOy9x7tRVZh+fETt4Y3clhErZj8g6VraC5ku+4pyHxtFztWor

sipa

Mailed as https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2012-June/001516.html