| 摘要 |
<p>A more secure CAPTCHA makes use of a distorted alphanumeric character string or strings that include one or more glyphs, pictures or symbols foreign to a target audience. Adding at least one of a glyph, picture or symbol makes recognition of the distorted string trivial since humans who would know which of the character set to expect, but a very difficult decision for a computer already struggling to decide where a character begins and ends, let alone identifying the character as being valid.</p> |
