Selective Picture-Based Encryption of Video Streams

Abstract

A method for encrypting a video stream in a video encoder is provided that includes receiving the video stream and randomly selecting pictures in the video stream as the video stream. In some examples, the number of randomly selected pictures may be based on a picture rate of the video stream. The method further includes encrypting the randomly selected pictures.

What is claimed is: 
     
         1 . A method comprising:
 randomly selecting, by a video encoder, a number of pictures from a group of pictures in a video stream, wherein the number of randomly selected pictures is based on a picture rate of the video stream; and   encrypting, by the video encoder, the randomly selected pictures from the group of pictures.   
     
     
         2 . The method of  claim 1 , further comprising setting a respective encryption flag of a set of encryption flags for each randomly selected picture,
 wherein encrypting the randomly selected pictures is based on the respective encryption flag for the randomly selected picture being set.   
     
     
         3 . The method of  claim 2 , further comprising resetting a picture group counter associated with the group of pictures after setting each encryption flag of the set of encryption flags. 
     
     
         4 . The method of  claim 3 , further comprising:
 incrementing the picture group counter after resetting the picture group counter; and   checking a first encryption flag of the set of encryption flags after incrementing the picture group counter,
 wherein the first encryption flag is associated with a current picture. 
   
     
     
         5 . The method of  claim 4 , further comprising encrypting the current picture in response to determining that the first encryption flag is set. 
     
     
         6 . The method of  claim 4 , further comprising refraining from encrypting the current picture in response to determining that the first encryption flag is not set. 
     
     
         7 . The method of  claim 1 ,
 wherein the number of randomly selected pictures is a first number, and   wherein a second number of pictures in the group of pictures is based on the picture rate of the video stream.   
     
     
         8 . The method of  claim 1 , wherein the group of pictures comprises a group of sequential pictures in the video stream. 
     
     
         9 . The method of  claim 1 , wherein each picture of the randomly selected pictures is encrypted before the respective picture is encoded. 
     
     
         10 . A video encoder comprising:
 a memory configured to store at least a portion of a video stream; and   one or more processors configured to:
 randomly select a number of pictures from a group of pictures in the video stream, wherein the number of randomly selected pictures is based on a picture rate of the video stream; and 
 encrypt the randomly selected pictures from the group of pictures. 
   
     
     
         11 . The video encoder of  claim 10 ,
 wherein the one or more processors are further configured to set a respective encryption flag of a set of encryption flags for each randomly selected picture, and   wherein the one or more processors are configured to encrypt the randomly selected pictures based on the respective encryption flag for the randomly selected picture being set.   
     
     
         12 . The video encoder of  claim 11 , wherein the one or more processors are further configured to reset a picture group counter associated with the group of pictures after setting each encryption flag of the set of encryption flags. 
     
     
         13 . The video encoder of  claim 12 , wherein the one or more processors are further configured to:
 increment the picture group counter after resetting the picture group counter; and   check a first encryption flag of the set of encryption flags after incrementing the picture group counter,
 wherein the first encryption flag is associated with a current picture. 
   
     
     
         14 . The video encoder of  claim 13 , wherein the one or more processors are further configured to encrypt the current picture in response to determining that the first encryption flag is set. 
     
     
         15 . The video encoder of  claim 13 , wherein the one or more processors are further configured to refrain from encrypting the current picture in response to determining that the first encryption flag is not set. 
     
     
         16 . The video encoder of  claim 10 ,
 wherein the number of randomly selected pictures is a first number, and   wherein a second number of pictures in the group of pictures is based on the picture rate of the video stream.   
     
     
         17 . A non-transitory computer-readable medium comprising instructions that, when executed by a video encoder, cause the video encoder to:
 randomly select a number of pictures from a group of pictures in a video stream, wherein the number of randomly selected pictures is based on a picture rate of the video stream; and   encrypt the randomly selected pictures from the group of pictures.   
     
     
         18 . The non-transitory computer-readable medium of  claim 17 , further comprising instructions that, when executed by the video encoder, cause the video encoder to set a respective encryption flag of a set of encryption flags for each randomly selected picture, and
 wherein the instructions to encrypt the randomly selected pictures comprise instructions to encrypt the randomly selected pictures based on the respective encryption flag for the randomly selected picture being set.   
     
     
         19 . The non-transitory computer-readable medium of  claim 18 , further comprising instructions that, when executed by the video encoder, cause the video encoder to:
 reset a picture group counter associated with the group of pictures after setting each encryption flag of the set of encryption flags; and   check a first encryption flag of the set of encryption flags after resetting the picture group counter,   wherein the first encryption flag is associated with a current picture.   
     
     
         20 . The non-transitory computer-readable medium of  claim 19 , further comprising instructions that, when executed by the video encoder, cause the video encoder to encrypt the current picture in response to determining that the first encryption flag is set.