Initializing Secure Environment…
Initializing Secure Environment…
Generate SHA-256, SHA-1, and MD5 cryptographic hash fingerprints for any PDF file to verify integrity, detect tampering, and prove a document has not been altered since a specific point in time. Hashing runs entirely in your browser — no file upload. The fingerprint is unique to the exact byte content of the file: any modification, no matter how small, produces a completely different hash.
Legal professionals use document hashes to prove a contract or evidence document has not been altered since signing. IT and compliance teams use hashes to verify that distributed policy documents have not been modified in transit. Journalists use hashes to prove source documents are authentic and unmodified. Accountants use hashes to create an audit trail showing financial documents have not been changed after review. The hash value is meaningless on its own — its value comes from comparing it to the hash of the same file at a different point in time.
A hash is a fixed-length string generated from the exact byte content of a file. SHA-256 produces a 64-character string. If even one character in the PDF changes, the hash changes completely. This makes hashes ideal for verifying a document has not been altered.
SHA-256 is recommended for security-sensitive use cases. MD5 and SHA-1 are faster but have theoretical vulnerabilities for adversarial forgery — they are still reliable for simple integrity verification of non-adversarial scenarios.
No. Hashing runs entirely in your browser's memory using the Web Crypto API. The file never leaves your device.
Yes. Generate and record the hash before distribution. If a recipient claims the document was altered, compare the hash of the received file to the original hash. Identical hashes prove the file is unchanged.