uniqid Generate a unique ID &reftitle.description; stringuniqid stringprefix"" boolmore_entropyfalse Gets a prefixed unique identifier based on the current time in microseconds. This function does not create random nor unpredictable strings. This function must not be used for security purposes. Use a cryptographically secure random function/generator and cryptographically secure hash functions to create unpredictable secure IDs. &reftitle.parameters; prefix Can be useful, for instance, if you generate identifiers simultaneously on several hosts that might happen to generate the identifier at the same microsecond. With an empty prefix, the returned string will be 13 characters long. If more_entropy is &true;, it will be 23 characters. more_entropy If set to &true;, uniqid will add additional entropy (using the combined linear congruential generator) at the end of the return value, which increases the likelihood that the result will be unique. &reftitle.returnvalues; Returns the unique identifier, as a string. &reftitle.examples; ]]> &reftitle.notes; This function does not generate cryptographically secure tokens, in fact without being passed any additional parameters the return value is little different from microtime. If you need to generate cryptographically secure tokens use openssl_random_pseudo_bytes. Under Cygwin, the more_entropy must be set to &true; for this function to work.