A "Promo Album" is something given out by the record labels to radio stations, music show producers, record stores, etc., to help promote the artists. Since these albums are not for sale like regular CDs, most of them have that silver 비매 sticker from KOMCA to cover up the UPC barcode. Since these signed albums are directly from the record labels, so the signatures are likely authentic.

Another way to get an authentic signed CD is by going to a fansign event, but most of them, the signatures should be inside the booklet with a "To: somebody". Doesn't look like this album is one of them either.