@Article {srj.tissec02,
    author = {P. Samarati and {M.K.} Reiter and S. Jajodia},
    title = {An Authorization Model for a Public Key Management Service},
    journal = {ACM Transactions on Information and System Security (TISSEC)},
    volume = {4},
    number = {4},
    month = {November},
    year = {2001}
}