SHA-1

A insecure hashing algorithm largely replaced by SHA256

• Weak to Preimage Attack
• Weak to Length Extension Attack Takes in a 512-bit input, return 160-bit output. Based off Merkle Damgard Construction

Get Sha1 Hash from file

sha1sum ./file

Algorithm

• With $F$ as a non-linear Compression Function that varies
• With a left-bit rotations
• With $W_i$ as the segment of the splitted plaintext message
• With $K_i$ as the segment of the round constant
• With $⊞$ as addition in $\mathrm{mod}{2}^{32}$

Uses

• SHACAL