Supporting integrity is another critical aspect of cryptography, ensuring that data remains unaltered and tamper-proof during transmission and storage. Cryptographic techniques for supporting integrity include:
Hash functions are cryptographic algorithms that produce a fixed-size output (hash value) from an input data of any size. The same input always produces the same hash value, and even a minor change in the input results in a completely different hash value. By verifying the hash value of received data against the expected value, integrity can be ensured.
Digital signatures are created using asymmetric encryption, where the sender uses their private key to sign the data. The receiver can then verify the signature using the sender's public key. Any alteration in the data would invalidate the signature, providing evidence of data tampering.
MACs are used to verify the integrity of messages or data blocks. They are generated by applying cryptographic hash functions to the message along with a secret key known to both sender and receiver. Any change in the data or the secret key would result in a different MAC.
PKI is a framework that supports the use of digital certificates and public key cryptography. Digital certificates issued by trusted Certificate Authorities (CAs) can be used to verify the authenticity and integrity of communication parties.
Time stamping is used to record the time at which a particular event occurs. In cryptography, digital signatures with timestamps help detect unauthorized changes made after the timestamp. Time-stamped data can serve as strong evidence of data integrity.
SHA algorithms, such as SHA-256 and SHA-3, are widely used cryptographic hash functions. They provide high-level security and ensure data integrity by generating fixed-size hash values for input data.
Data integrity checks, like cyclic redundancy checks (CRC), are used to verify the integrity of data by comparing checksums. Any changes in the data during transmission will result in a different checksum value.
Using secure communication protocols like SSL/TLS, IPsec, and SSH can prevent data tampering during transmission. These protocols encrypt the data and provide mechanisms for ensuring data integrity.
Implementing secure backup and storage mechanisms protects data from unauthorized alterations. Securely storing cryptographic keys and regularly verifying data integrity during backup and restore processes are essential practices.
By incorporating these cryptographic techniques, organizations can establish and maintain data integrity, ensuring that data remains unaltered and trustworthy throughout its lifecycle.