With an advancement in biomedical applications, many images are communicated over the public networks. Therefore, these medical images are prone to various security threats. Development of end to end secure communication protocol for these medical images is found to be a challenging task. Therefore, many researchers have proposed various image medica image encryption techniques to provide end to end security of medical images. However, the existing approaches of block-based recovery of the secret through progressive sharing paradigm have support for limited threshold value of the chosen blocks out of the total number of the blocks during the communication of the image. Most of the suggested scheme has fixed threshold value for the blocks during recovery of secret; works good for a limited threshold (k) value out of number of blocks (n) in which secret has been divided for security. A novel threshold based (any value of k and n) blockwide recovery of secret in progressive secret sharing has been introduced and analyzed for distributed environment. The proposed threshold block wise splitting using progressive visual secret sharing (T-BPVSS) achieves any general higher value of threshold for recovery of secret medical images. Proposed scheme is tested based on various parameters such as varying values of threshold for recovery of secret during enhanced security scenario, as well as changing dimensions of the images and introducing noise in the images. A detailed distributed computing recovery solution is also suggested for the original secret by using distribution technique of shares across the networks of computers. The scheme satisfies for perfect security condition in distributed environment using at least minimum decided threshold numbers of participants (k) before revealing any of the blocks of secret medical image.

随着生物医学应用的进步，许多图像通过公共网络进行通信。因此，这些医学影像容易受到各种安全威胁。发现为这些医学图像开发端到端安全通信协议是一项具有挑战性的任务。因此，许多研究人员提出了各种图像医学图像加密技术来提供医学图像的端到端安全性。然而，现有的通过渐进共享范式的基于块的秘密恢复方法支持在图像通信期间从块的总数中选择块的有限阈值。大多数建议的方案在恢复秘密期间对块具有固定的阈值；适用于为安全而划分秘密的块数 (n) 中的有限阈值 (k) 值。已经针对分布式环境引入并分析了一种新颖的基于阈值（k 和 n 的任何值）块范围内的渐进式秘密共享中的秘密恢复。所提出的使用渐进式视觉秘密共享（T-BPVSS）的阈值块分割实现了用于恢复秘密医学图像的任何一般更高的阈值。所提出的方案基于各种参数进行测试，例如在增强的安全场景中改变秘密恢复的阈值，以及改变图像的尺寸和在图像中引入噪声。还提出了一个详细的分布式计算恢复解决方案，通过使用跨计算机网络的共享分配技术来恢复原始秘密。该方案在泄露任何秘密医学图像块之前使用至少最小确定的参与者阈值数量 (k) 满足分布式环境中的完美安全条件。