$uuid[^math:uuid[]]^uuid.length[]
$uid64[^math:uid64[]]^uid64.length[]
^math:md5[123]
^math:sha1[123]
^math:digest[sha1;123; $.hmac[pwd] ]
^math:digest[md5;123; $.hmac[pwd] ]
^math:digest[sha1;123; $.hmac[very-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-key] ]
^math:digest[md5;123; $.hmac[very-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-long-key] ]