{"id":9343,"date":"2023-12-20T07:43:18","date_gmt":"2023-12-20T12:43:18","guid":{"rendered":"https:\/\/faisalkhan.com\/?page_id=9343"},"modified":"2024-02-24T09:13:37","modified_gmt":"2024-02-24T14:13:37","slug":"sha256","status":"publish","type":"page","link":"https:\/\/faisalkhan.com\/learn\/payments-wiki\/sha256\/","title":{"rendered":"SHA256"},"content":{"rendered":"\n
SHA-256, or Secure Hash Algorithm 256-bit, is a cryptographic hash function that is widely used in various security applications and protocols, including SSL\/TLS and in the blockchain technology of Bitcoin. Here’s a comprehensive explanation to satisfy your curiosity:<\/p>\n\n\n\n
It’s important to clarify that SHA-256 is not an encryption algorithm but a cryptographic hash function. While encryption is about encoding data so that it can be decoded later, hashing is a one-way process to create a unique digital fingerprint of data. Here are a couple of examples to illustrate how SHA-256 hashing works:<\/p>\n\n\n\n
When you pass the string “Hello, World!” through a SHA-256 hash function, it produces a unique, fixed-length string of characters. Even a small change in the input (like “hello, world!” with a lowercase ‘h’) will result in a completely different hash.<\/p>\n\n\n\n
This way, even if someone gains access to the database, they only see the hash values, not the actual passwords. Due to the one-way nature of SHA-256, they can’t reverse-engineer the hashes to find out the passwords.<\/p>\n\n\n\n
Here are the SHA-256 hashes for the two example inputs:<\/p>\n\n\n\n
dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f<\/code><\/li>\n<\/ul>\n\n\n\n\n- For “hello, world!” (note the lowercase ‘h’):<\/li>\n<\/ol>\n\n\n\n
\n- SHA-256 Hash:
68e656b251e67e8358bef8483ab0d51c6619f3e7a1a9f0e75838d41ff368f728<\/code><\/li>\n<\/ul>\n\n\n\nObserve how a small change in the input results in a completely different hash. This illustrates the sensitivity of the SHA-256 algorithm to any alteration in the input data.<\/p>\n\n\n\n
So why do we use hash functions? One reason is to help verify the authenticity of a message. For example, let\u2019s say you download a file from the internet and the website tells you the SHA-256 hash value of the file. You can then run the file through the SHA-256 hash function yourself and compare the resulting hash value to the one provided by the website. If they match, it means the file is authentic and has not been tampered with.<\/p>\n\n\n\n
Another reason we use hash functions is for password security. When you create a new password, the website or service you\u2019re using will run your password through a hash function and store the resulting hash value in its database. When you log in and enter your password, the website will run the entered password through the same hash function and compare the resulting hash value to the one stored in its database. If they match, it means you entered the correct password. This way, even if someone hacks into the website\u2019s database and steals the stored hash values, they won\u2019t be able to figure out what the actual passwords are because the hash function is a one-way process (it\u2019s easy to generate a hash value from a message, but it\u2019s practically impossible to generate the original message from the hash value).<\/p>\n\n\n\n
SHA-256 (and other SHA algorithms) are preferred for a few reasons:<\/p>\n\n\n\n
\n- Security: SHA-256 is considered to be very secure. It\u2019s a \u201ccryptographic hash function,\u201d which means it\u2019s designed to be very difficult to reverse. In other words, it\u2019s easy to generate a hash value from a message, but it\u2019s practically impossible to generate the original message from the hash value.<\/li>\n\n\n\n
- Speed: SHA-256 is also relatively fast, which makes it suitable for use in many different applications.<\/li>\n\n\n\n
- Widely used: SHA-256 is widely used and supported. Many different organizations and websites use SHA-256 for things like verifying file integrity and secure communication.<\/li>\n\n\n\n
- Collision resistance: A \u201ccollision\u201d occurs when two different input messages produce the same hash value. It\u2019s important for a hash function to be collision-resistant, meaning it should be very unlikely that two different input messages will produce the same hash value. SHA-256 is considered to be collision-resistant.<\/li>\n\n\n\n
- Hash length: The hash value produced by SHA-256 is 256 bits long, which is why it\u2019s called SHA-256. This means it\u2019s made up of 256 1s and 0s, and is typically represented as a 64-character hexadecimal number.<\/li>\n\n\n\n
- Non-reversible: As I mentioned earlier, one of the key features of SHA-256 (and other hash functions) is that it\u2019s a one-way process. It\u2019s easy to generate a hash value from a message, but it\u2019s practically impossible to generate the original message from the hash value. This makes it very difficult for someone to reverse the process and figure out what the original message was.<\/li>\n\n\n\n
- Fixed-size output: The output of the SHA-256 function is always the same length (256 bits), no matter how long or short the input message is. This is because the hash function processes the input message in a fixed number of steps, and at each step it combines the input message with a fixed set of numbers and performs a series of mathematical operations.<\/li>\n\n\n\n
- Collision attacks: Despite being collision-resistant, it\u2019s still theoretically possible for two different input messages to produce the same hash value (this is called a \u201ccollision\u201d). However, it would be extremely difficult and time-consuming to find two input messages that produce the same hash value using SHA-256. There are more advanced hash functions available that are even more resistant to collision attacks, but they are typically slower and less practical to use.<\/li>\n<\/ol>\n\n\n\n
Overall, the combination of security, speed, and widespread use makes SHA-256 a preferred choice for many different applications.<\/p>\n\n\n\n
Conclusion<\/h3>\n\n\n\n
SHA-256 stands as a cornerstone in the field of cryptography, providing a reliable and secure way to ensure data integrity and security in a wide range of digital applications. Its complexity and computational intensity make it a robust tool against tampering, fraud, and a variety of cyber threats. Your fascination with SHA-256 is well-founded, as it represents a critical component in the infrastructure of modern digital security.<\/p>\n","protected":false},"excerpt":{"rendered":"
SHA-256, or Secure Hash Algorithm 256-bit, is a cryptographic hash function that is widely used in various security applications and protocols, including SSL\/TLS and in the blockchain technology of Bitcoin. Here’s a comprehensive explanation to satisfy your curiosity: What is SHA-256? Importance Usage Difficulty in Solving Solvability and Computing Time Is SHA-256 the Default? It’s […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3611,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"blocksy_meta":[],"featured_image_urls":{"full":"","thumbnail":"","medium":"","medium_large":"","large":"","1536x1536":"","2048x2048":"","gb-block-post-grid-landscape":"","gb-block-post-grid-square":"","yarpp-thumbnail":""},"post_excerpt_stackable":"
SHA-256, or Secure Hash Algorithm 256-bit, is a cryptographic hash function that is widely used in various security applications and protocols, including SSL\/TLS and in the blockchain technology of Bitcoin. Here’s a comprehensive explanation to satisfy your curiosity: What is SHA-256? Definition: SHA-256 is part of the SHA-2 family of cryptographic hash functions designed by the National Security Agency (NSA) in the United States. It generates a unique, fixed-size 256-bit (32-byte) hash. Think of it like a digital fingerprint for data. Importance Security: It’s crucial for maintaining data integrity in digital communications. The unique hash ensures that even a small…<\/p>\n","category_list":"","author_info":{"name":"Faisal Khan","url":"https:\/\/faisalkhan.com\/author\/nomismad\/"},"comments_num":"0 comments","featured_image_urls_v2":{"full":"","thumbnail":"","medium":"","medium_large":"","large":"","1536x1536":"","2048x2048":"","gb-block-post-grid-landscape":"","gb-block-post-grid-square":"","yarpp-thumbnail":""},"post_excerpt_stackable_v2":"
SHA-256, or Secure Hash Algorithm 256-bit, is a cryptographic hash function that is widely used in various security applications and protocols, including SSL\/TLS and in the blockchain technology of Bitcoin. Here’s a comprehensive explanation to satisfy your curiosity: What is SHA-256? Definition: SHA-256 is part of the SHA-2 family of cryptographic hash functions designed by the National Security Agency (NSA) in the United States. It generates a unique, fixed-size 256-bit (32-byte) hash. Think of it like a digital fingerprint for data. Importance Security: It’s crucial for maintaining data integrity in digital communications. The unique hash ensures that even a small…<\/p>\n","category_list_v2":"","author_info_v2":{"name":"Faisal Khan","url":"https:\/\/faisalkhan.com\/author\/nomismad\/"},"comments_num_v2":"0 comments","yoast_head":"\n
SHA256 - Faisal Khan<\/title>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\t\n