Question

Discuss how different types of encryption systems work, and explain how digital signatures provide the means for creating legally-enforceable contracts.

Answer 1

There are four encryption methods on the basis of keys used, key length, and size of data blocks encrypted.

1. Advanced Encryption Standard (AES)

Advanced Encryption Standard is a symmetric encryption algorithm that encrypts fixed blocks of data (of 128 bits) at a time. The keys used to decipher the text can be 128-, 192-, or 256-bit long. The 256-bit key encrypts the data in 14 rounds, the 192-bit key in 12 rounds, and the 128-bit key in 10 rounds. Each round consists of several steps of substitution, transposition, mixing of plaintext, and more. AES encryption standards are the most commonly used encryption methods today, both for data at rest and data in transit.

2. Rivest-Shamir-Adleman (RSA)

Rivest-Shamir-Adleman is an asymmetric encryption algorithm that is based on the factorization of the product of two large prime numbers. Only someone with the knowledge of these numbers will be able to decode the message successfully. RSA is often used in digital signatures but works slower when large volumes of data need to be encrypted.

3. Triple Data Encryption Standard (TripleDES)

Triple Data Encryption Standard is a symmetric encryption and an advanced form of the DES method that encrypts blocks of data using a 56-bit key. TripleDES applies the DES cipher algorithm three times to each data block. TripleDES is commonly used to encrypt ATM PINs and UNIX passwords.

4. Twofish

Twofish is a license-free encryption method that ciphers data blocks of 128 bits. It’s considered the successor to the Blowfish encryption method that ciphered message blocks of 64 bits. Twofish always encrypts data in 16 rounds regardless of the key size. Though it works slower than AES, the Twofish encryption method continues to be used by many file and folder encryption software solution.

how digital signatures provide the means for creating legally-enforceable contracts.:

The E-Sign Act states that signatures should not be denied legal validity solely because they are electronic, which means that a contract that is signed electronically can be brought into trial. However, a judge’s willingness to accept that contract will depend on how the electronic document was signed.