History and Overview of SHA384

SHA384 was introduced as part of the SHA-2 family by the National Institute of Standards and Technology (NIST) in 2001. Designed to offer enhanced security over earlier hash functions, SHA384 produces a 384-bit hash, striking a balance between output length and security. Its longer hash output provides a greater degree of collision resistance compared to SHA256, making it suitable for applications requiring high security.

Key historical milestones:

• 2001:SHA-2 family, including SHA384, is published as a secure replacement for SHA1.
• Early 2000s:Adopted in various security protocols and applications due to its enhanced collision resistance.
• Recent Years:SHA384 is used in environments where stronger security is needed, such as digital signatures and secure communications.

What is SHA384?

SHA384 is a cryptographic hash function that takes an input of any length and produces a fixed 384-bit (48-byte) hash value, typically rendered as a 96-character hexadecimal number. Like all SHA-2 functions, it is deterministic and designed to be one-way: the same input always produces the same output, but it is computationally infeasible to retrieve the original input from the hash.

Core purposes of SHA384:

• Data Integrity:Ensure that data remains unaltered during transmission or storage.
• Digital Fingerprinting:Create a unique signature for files, messages, or digital documents.
• Security Applications:Used in secure protocols, digital signatures, and other cryptographic systems where high collision resistance is crucial.

How Does SHA384 Work?

SHA384 processes data through several steps to generate a secure hash:

1. Padding:The input message is padded so that its length is congruent to 896 modulo 1024. Padding begins with a "1" bit followed by "0" bits until the message is of the required length.
2. Length Appending:A 128-bit representation of the original message length is appended to the padded message.
3. Initialization:Eight 64-bit words are initialized with SHA384-specific constants. These constants differ from those used in SHA512, though both belong to the same family.
4. Processing in 1024-bit Blocks:The padded message is divided into 1024-bit blocks. Each block is processed through 80 rounds of operations that involve bitwise logical functions, modular additions, and shifts to update the internal state.
5. Output:The final state is concatenated and then truncated to 384 bits, yielding the hash value represented as a 96-character hexadecimal string.

Below is a simplified pseudocode representation:

function SHA384(message) {
  paddedMessage = pad(message); // Pad the message to required length
  H0, H1, H2, H3, H4, H5, H6, H7 = initialConstants(); // SHA384-specific constants
  for (each 1024-bit block in paddedMessage) {
    (H0, H1, H2, H3, H4, H5, H6, H7) = processBlock(block, H0, H1, H2, H3, H4, H5, H6, H7);
  }
  return truncate(concatenate(H0, H1, H2, H3, H4, H5, H6, H7), 384);
}
  

SHA384 Examples

• Example 1:
  Input:"hello"
  SHA384 Hash:59e1748777448c69de6b800d7a33bbfb9ff1b463e44354c3553bcdb9c666fa90125a3c79f90397bdf5f6a13de828684f
• Example 2:
  Input:"BMR ONLINE TOOLS"
  SHA384 Hash:1c83eabf0098b396446f44519c3a33da09ccec5d3af2e215853c303b228500e1d7b34ce2820fbdea9a66a2fb6f38699b

These examples demonstrate that even slight differences in input result in completely different, fixed-length hash values.

Why SHA384 Decryption Is Impossible

• One-Way Function:SHA384 is designed to be irreversible. Once data is processed into a hash, recovering the original input is computationally infeasible.
• Security Through Irreversibility:Its one-way design ensures that even if an attacker obtains the hash, they cannot reconstruct the original data.
• Hash Lookup:Verification is performed by comparing the hash of an input to a pre-stored hash value, not by decrypting the hash.

This irreversible design is what makes SHA384 effective for ensuring data integrity but also means that decryption of the hash is not possible.

Hash Lookup vs. Decryption

Hash Lookup:Involves computing the hash of an input and comparing it to a database of precomputed hash values to verify data integrity or authenticate users.

Decryption:Refers to reversing an encryption process to recover original data. Since SHA384 is a one-way hash function, there is no decryption; instead, only hash lookup is possible.

Limitations and Best Practices

• Collision Resistance:SHA384 offers strong collision resistance, though no hash function is completely immune to collisions.
• Usage Recommendations:SHA384 is ideal for applications requiring high security and data integrity, such as digital signatures and secure communications.

Best Practices:For high-security applications, SHA384 is a reliable choice. However, if a shorter hash is needed, consider using SHA224 or SHA256. Always use the most appropriate algorithm for your security requirements.

Key Takeaways & Learnings

SHA384 is a powerful hash function that produces a 384-bit hash value, providing enhanced collision resistance and security. Its one-way nature means that decryption is impossible, making hash lookup the only practical method for verifying data integrity.

SHA384 is widely used in high-security applications such as digital signatures, secure communications, and blockchain technologies. AtBMR ONLINE TOOLS, we offer advanced encryption and hashing solutions that leverage robust algorithms like SHA384 to ensure your data remains protected and your digital processes secure.