Methods and apparatus for secure distribution of software
Software is securely distributed with limited usage rights. The software may be an executable program and/or one or more data files such as image or multimedia data files. The software includes an access control object which prevents at least some usage of the software without use of a first access control code. The first access control code is produced based on selected information characteristic of the user's computer system. The access control code is produced in a server computer to which the user directs a request for the access control code. The user makers a payment to receive the access control code, which is then downloaded to the user's computer system.
1 . A software package, comprising:
a software object comprising a data object having a first set of features and a second set of features, the first set of features being encrypted and the second set of features being unencrypted; and
a signature readable by a predetermined executable serving to control access to the encrypted first set of features.
2 . The software package of claim 1 , wherein the data object comprises music data.
3 . The software package of claim 2 , wherein the music data is encoded as a plurality of frequency coefficients produced by a discrete cosine transform, the coefficients including relatively low frequency coefficients and relatively high frequency coefficients, the relatively high frequency coefficients being encrypted and the relatively low frequency coefficients being unencrypted.
4 . The software package of claim 2 , wherein the music data is arranged in a plurality of subbands, at least some of the subbands of data being encrypted and others of the subbands being unencrypted.
5 . The software package of claim 2 , wherein the music data is frequency domain data, at least some of the frequency domain data being encrypted and other of the frequency domain being unencrypted.
6 . The software package of claim 1 , wherein the data object comprises image data.
7 . The software package of claim 6 , wherein the image data is encoded as a plurality of frequency coefficients produced by discrete cosine transform, the coefficients including relatively low frequency coefficients and relatively high frequency coefficients, the relatively high frequency coefficients being encrypted and the relatively low frequency coefficients being unencrypted.
8 . The software package of claim 6 , wherein the image data comprises color components, at least some of the color components being encrypted.
9 . The software package of claim 8 , wherein at least one of the color components is unencrypted.
10 . The software package of claim 7 , wherein the image data further comprises an unencrypted luminance component, and wherein all of the color components are encrypted.
11 . The software package of claim 6 , wherein the image data comprises line data, at least some of the line data being encrypted.
12 . The software package of claim 6 , wherein the image data is arranged in a plurality of lines, at least portions of some of the lines being encrypted and at least other portions of other lines being unencrypted.
13 . The software package of claim 6 , wherein the image data is arranged at least in part as a plurality of blocks, at least one of the blocks being encrypted.