Biblio

Bitcoin, a decentralized cryptographic currency that has experienced proliferating popularity over the past few years, is the common denominator in a wide variety of cybercrime. We perform a measurement analysis of CryptoLocker, a family of ransomware that encrypts a victim's files until a ransom is paid, within the Bitcoin ecosystem from September 5, 2013 through January 31, 2014. Using information collected from online fora, such as reddit and BitcoinTalk, as an initial starting point, we generate a cluster of 968 Bitcoin addresses belonging to CryptoLocker. We provide a lower bound for CryptoLocker's economy in Bitcoin and identify 795 ransom payments totalling 1,128.40 BTC (\$310,472.38), but show that the proceeds could have been worth upwards of \$1.1 million at peak valuation. By analyzing ransom payment timestamps both longitudinally across CryptoLocker's operating period and transversely across times of day, we detect changes in distributions and form conjectures on CryptoLocker that corroborate information from previous efforts. Additionally, we construct a network topology to detail CryptoLocker's financial infrastructure and obtain auxiliary information on the CryptoLocker operation. Most notably, we find evidence that suggests connections to popular Bitcoin services, such as Bitcoin Fog and BTC-e, and subtle links to other cybercrimes surrounding Bitcoin, such as the Sheep Marketplace scam of 2013. We use our study to underscore the value of measurement analyses and threat intelligence in understanding the erratic cybercrime landscape.

This paper proposes a novel plan of compacting encoded pictures with helper data. The substance manager scrambles the first uncompressed pictures furthermore creates some helper data, which will be utilized for information pressure and picture recreation. At that point, the channel supplier who can't get to the first substance may pack the encoded information by a quantization technique with ideal parameters that are gotten from a piece of helper data and a pressure proportion mutilation criteria, and transmit the packed information, which incorporate a scrambled sub-picture, the quantized information, the quantization parameters and an alternate piece of assistant data. At recipient side, the key picture substance can be reproduced utilizing the packed scrambled information and the mystery key.