App::FuguSeed::Codewords(3p) Perl Library Manual App::FuguSeed::Codewords(3p)

App::FuguSeed::Codewords - the 44 codewords of a Standard SeedQR

    use App::FuguSeed::Codewords;
    my @codewords = App::FuguSeed::Codewords->encode($digits);

App::FuguSeed::Codewords turns the 48 digits of a 12-word seed into the codewords of the QR code. The code is QR version 2, error correction level L, in numeric mode, with one block of 44 codewords: 34 of data and 10 of error correction.

The data bit stream holds the mode indicator, the character count, the 16 groups of 3 digits, the terminator, and the zero bits to a codeword boundary. The two pad codewords fill the rest of the 34 in turn. The 10 error correction codewords are the Reed-Solomon remainder of the data codewords over the field GF(256).

Every method is a class method, and every method is pure: it takes values and it returns values. The module touches no stream, and it loads no module. Each constant of the QR standard sits at the top of the module, and a comment names the table that it comes from.

encode($digits) returns the 44 codewords of the digit string $digits: the 34 data codewords first, then the 10 error correction codewords. Each codeword is a number from 0 to 255.

encode() returns 44 numbers.

encode() expects the 48 digits of App::FuguSeed::Mnemonic. With another input, the caller gets a code that no reader decodes.

App::FuguSeed::Mnemonic, App::FuguSeed::Matrix, and ISO/IEC 18004, the QR standard.

Dick Olsson <hi@senzilla.io>

2026-09-23 OpenBSD