Password schemata

Schemata are represented as nested lists with the following grammar. items is the root production.








character classcharacters


Name Meaning
“word” the literal string "word"
delimiter a string which will be used between every item in this counted group
count an integer of the number of times to repeat the items in this group
character class one of printable, alphanumeric, digit, letter, uppercase, lowercase, or symbols corresponding to different ranges of ASCII characters
characters a string representing a set of characters


All examples are given in JSON-mini format.

A basic password of 12 alphanumeric characters would be represented like so:

[[12, alphanumeric]]

In this example, there is one item in the items list, and that item is [12, alphanumeric]. The string "alphanumeric" is a character class.

Another simple example is four space-delimited words:

[[" ", 4, word]]

Again, there is one item. Normally there is no delimiter between repeated elements, but an item where the first element is a string indicates that its contents should be delimited with the first element as a delimiter. The string word is itself a special item which indicates that something should be selected from the word list.

A slightly more complex example is 12 hexadecimal digits:

[[12, [digit, "abcdef"]]]

And again, there is one item. The list [digit, "abcdef"] is a character-sets with two character-sets in it: digit is a character class character-set, and "abcdef", since it does not match any character class name, matches the literal characters.

Another more complex example is a series of four words, separated by spaces, and with each word followed by a single digit:

[[" ", 4, word, digit]]

Here, there are multiple nested items in the item [" ", 4, word, digit]: word and digit. These two items will be concatenated together before being delimited by spaces. For example, this might produce the string spam1 spam2 eggs3 spam4.

One way of expressing a 12-character password that requires at least one letter and one digit is:

[[uppercase, lowercase], digit, [10, alphanumeric]]

This series of items has three items in it: [uppercase, lowercase], digit, and [10, alphanumeric]. For example, this might produce the string a1spam9EGGS9.