A binary bit-string is encoded in a circular image. The circular image encodes substrings of the bit-string in sectors of the circular image and includes redundant bits, error correcting codes, and metadata pertaining to the encoding scheme. To encode the bit-strings, a circular image is generated that includes a center ring and a first ring. Outward from the first ring, additional rings represent bits in the bit-string according to the width of each ring. The exterior of the image includes an outer boundary ring. The width of the boundary rings is used to define the widths representing the value of each ring. To extract a bit-string from an image, the center of the circular image is identified and a direction is selected to evaluate the image outward, determining the boundaries of each ring. The boundaries are analyzed to determine the width of each ring and the encoded bit values.