When doing data exchange among different parties, there is a frequent need of encrypting data or file and sending it to partner and asking partner to use corresponding key to decrypt the data or file. A famous way of exchanging data is using asymmetric keys where no secret key needs to be shared. One party can just use the public key shared by partner to encrypt the data and the other party uses the private key to decrypt the data.Today, we will introduce how to use PGP to encrypt and decrypt data on MacOS. Pretty Good Privacy (PGP) is an encryption system used for both sending encrypted ...

The history of computer virus is the same as computer history. With more and more powerful computers, virus also are smarter and harder to be detected and killed. They have big impact on data security and system usability. We introduce 10 notorious computer virus in the history.1. CreeperIn 1971, the Creeper virus, an experimental self-replicating program, is written by Bob Thomas at BBN Technologies. Creeper infected DEC PDP-10 computers running the TENEX operating system. Creeper gained access via the ARPANET and copied itself to the remote system where the...

Secure communication has become a vital requirement on the Internet. Lots of information transferred through the Internet are sensitive data such as financial transactions, medical information, media streaming etc. To ensure security of data transferred on the Internet, a few secure protocols have been designed including SSL/TLS and IPsec. Many large websites in the world have adopted TLS. Apart from SSL/TLS, there is some other protocol designed to be used in special cases. One of them is the DTLS -- Datagram Transport Layer Security protocol.What is DTLSDTLS is a secure data transfer pr...

We need to build a password protected website frequently such as an internal website within the team, demo website. Here what we are talking about is password protection in Nginx server level instead of application level registration and login. We are going to use Nginx server configuration and htpasswd file to achieve password authentication.The final result looks like below(Different browsers may have different interfaces):If the authentication fails, it will report a HTTP error: 401 Authorization Required.To achieve this function, we need to modify server configuration and create the userna...

OAuth 2.0 is an authorization mechanism, it's ,mainly used for issuing access token. There are 4 ways to obtain access token as per RFC 6749.Authorization codeImplicitPasswordClient credentialsThe third party application must obtain a client id and client secret from the target service before obtaining access token no matter which method to use. This is to prevent token to be used maliciously.Authorization codeWith this method, the third party application must first get an authorization code and then use this authorization code to exchange the access token. This is the most commonly used metho...

Sometimes if you want to hide some important files on your computer which you don't want others to see, how would you do that? Find a professional tool? Set password for some folders? Change the file properties to hidden? They are possible, but they may not be so convenient or so secure. Here we share with you how to hide a file in a picture.Prerequisites1 picture for example : test.jpg1 test file, for example : test.txtWinRARStepsPrepare the picture test.jpg and test file test.txtUse WinRAR to compress test.txt to test.rarOpen command prompt : Start->Run->Type "cmd", then cd to the dire...

Spam comments are annoying and notorious. They are either malicious data from hackers to exploit the loopholes of the site or advertisements posted by robots. These kinds of comments have their own features and patterns, if we are careful enough, we can find ways to block most of them although it's not so easy.To block the comment with malicious executable codes such as JavaScript, we should remember one rule : never trust user input. So wherever there are user inputs, we need to check the validity of the data, we should escape the data inputted by users and remove unnecessary HTML tags from t...

Cheating has been around as long as gambling itself, which is surely since the dawn on of time. Cheating in casinos, both land based and online, can prove a huge problem, not only for those playing against the cheater, but for the individual casino operators, as well as the industry in its entirety. Preventing cheating makes casino play fairer for all involved, both operators and their clients.Fortunately, in today's day and age, we have excellent, highly developed technology that can assist casino operators in pinpointing, profiling and ultimately catching the cheaters amongst their clientele...