Content Security Policy (CSP)
With Content Security Policy, you create an allow list of sources of trusted content in the HTTP headers, pre-approving certain servers for content loaded into a webpage and instructing the browser to only execute or render resources from those sources. This can be used to prevent malicious content from being injected into sites.
HTTP Strict Transport Security (HSTS)
HSTS policy protects against variants of man-in-the-middle attacks that can strip TLS out of communications with a server, leaving the user vulnerable. HSTS does this by allowing sites to specify that the browser should always use a secure connection to the server.
The meta name="referrer" tag lets you specify what information about a webpage should be passed in the HTTP header to any request sent from the page.
Web Cryptography API
Web Crytography API provides basic cryptographic operations in web applications, such as hashing, signature generation and verification, and encryption and decryption.
Transport Layer Security (TLS)
TLS, the successor to SSL, is a protocol that provides communications privacy and security between two applications communicating over a network. For more info about the TLS protocol, check out the Windows Dev Center.