Bencode

Used by BitTorrent to encode loosely structured data

• Every value has only one possible bencoding

Supported types

4 data types supported:

• Integers
• Byte strings
• Lists
• Dictionaries

List and dictionaries may contain other lists and dictionaries, no restrictions

Format

Uses ASCII characters as delimiters and digits

• Integers are encoded as i<base 10 ASCII>e
  • Leading zeroes not allowed
  • Negative values have a - at the start
• Byte strings are encoded as <length>:<content>
  • Length encoded in base 10, must be non-negative
  • Does not handle non-ASCII characters
• Lists are encoded as l<contents>e
  • <contents> is all the items in the list, bencoded, concatenated without a separator
• Dictionaries are encoded as d<contents>e
  • Like lists, contents are encoded as <key1><value1><key2><value2>, without a separator