All Dogecoin addresses are public key hashes. Unlike bitcoin addresses, which are 27 to 33 characters long, Dogecoin addresses are a string of 34 numbers and letters (both upper and lower case), starting with the letter D. A public key is the Dogecoin address to which other users can send Dogecoins. A private key, however, allows full access to the Dogecoin wallet; it must be kept secret and secure