I. Introduction
Blockchain technology has changed the way we verify an e-mail, by using hash function to certify an e-mail received is exact the same as the one intended by its sender.
II. Hash Function
Some companies from Taiwan have started this service, using hash function to produce a “key” for the original e-mail. The key was produced according to the “value” including the original e-mail’s content, attachment, date and time, and addresses of sender and receivers [3][4][6].
The “key” is then stored on the internet, and receiver of the e-mail may produce another “key” using the e-mail received, comparing if the two keys are exact [1].
III. Verification
There have been efforts to facilitate the process of verification. For instance, ChkSender, which is one of the pioneer firms in this domain, provides an extension for Gmail users in desktop Chrome browser to produce “keys” and to handle comparison. It distinguishes even the smallest difference according to review [2].
IV. Verifying Other Documents
Not only e-mail, but school transcript, business license, and other documents face the challenge of counterfeit [5]. The characteristic of hash function in blockchain technology that incorporates the unique combination of time, place, agents and content into a “key” has make comparison much easier [7]. Although spam filter helps to distinguish spam messages, hash function enables the real message to stand out.
V. Reference
[1] Hash是什麼？5分鐘帶你了解區塊鏈雜湊相關的知識. (2019, April 10). Retrieved March 25, 2020, from https://blockbar.io/blockchain/hash是什麼-what-is-hash/
[2] Kan, M. (2020, March 3). 電子郵件一秒變存證信函 ChkSender輕鬆幫Gmail上鏈升級. Retrieved March 25, 2020, from https://www.winfohub.com/lifestyle/9165/
[3] Liu, J. (2019, July 18). 台灣區塊鏈技術公司「區塊科技」推存證上鏈 App：搶攻價值 6 億美元的數位鑑識領域商機. Retrieved March 25, 2020, from https://www.blocktempo.com/taiwan-blockchain-tech-company-developed-app-for-evidence-onchain/
[4] 楊 文君 (Ed.). (2020, February 7). 電子郵件詐騙頻傳 台灣區塊鏈新創研發獨步全球解決方案. Retrieved March 25, 2020, from https://www.rti.org.tw/news/view/id/2053259
[5] 法務部調查局 公共事務室. (2019, April 24). 全球首創！調查局以區塊鏈保護司法鑑定及雲端取證資料證據力. Retrieved March 25, 2020, from https://www.mjib.gov.tw/news/Details?Module=1&id=440
[6] 許 明恩. (2020, February 5). 別再靠紙本替數位資料存檔 — 專訪區塊科技執行長黃敬博. Retrieved March 25, 2020, from https://blocktrend.substack.com/p/–6e5
[7] 陳 雲峯. (2019, August 30). 《區塊鏈司法存證應用白皮書》解讀——區塊鏈存證的應用場景和挑戰. Retrieved March 25, 2020, from https://www.chainnews.com/zh-hant/articles/184053154902.htm