Embodiments of the present invention relate to encryption key allocation with additional security elements to lessen vulnerability to certain attacks. In one embodiment, a method and computer program product is provided for broadcast encryption. A key bundle encoded in a non-transient machine-readable medium is received. The key bundle comprises a first cryptographic key and an associated first cryptographic function identifier. Encrypted content is received. A key block corresponding to a subset difference tree is received. A first cryptographic triple function corresponding to the first cryptographic function identifier is determined. The subset difference tree is traversed using the first cryptographic key and the first cryptographic triple function to obtain a content cryptographic key. The content cryptographic key is applied to the encrypted content to obtain decrypted content.