Let's elaborate on the key types, master key, keypair, public key, private key, secret key, write/read key, types of symmetric and asymmetric algorithms with their key sizes, digest types, and digital certificates like X.509, as well as the difference between certificates and keys, and digital signatures.
Master Key
Type: Typically a secret key (symmetric).
Usage: Used to derive or encrypt other keys in a key management system.
Example: Key Encryption Key (KEK).
Keypair
Type: Asymmetric (consists of a public key and a private key).
Usage: Public key for encryption/signature verification, private key for decryption/signing.
Example: RSA keypair.
Public Key
Type: Asymmetric.
Usage: Encrypt data, verify digital signatures.
Example: RSA public key.
Private Key
Type: Asymmetric.
Usage: Decrypt data, create digital signatures.
Example: RSA private key.
Secret Key
Type: Symmetric.
Usage: Used for both encryption and decryption.
Example: AES key.
Write/Read Key
Type: Can be secret keys (symmetric) or part of a keypair (asymmetric).
Usage:
Symmetric: Same key for both writing (encrypting) and reading (decrypting).
Asymmetric: Public key for writing (encrypting), private key for reading (decrypting).
Symmetric Algorithms
AES (Advanced Encryption Standard)
Key Sizes: 128, 192, 256 bits.
DES (Data Encryption Standard)
Key Size: 56 bits.
3DES (Triple DES)
Key Sizes: 112, 168 bits.
Blowfish
Key Sizes: 32 to 448 bits.
Twofish
Key Sizes: 128, 192, 256 bits.
Asymmetric Algorithms
RSA (Rivest-Shamir-Adleman)
Key Sizes: 1024, 2048, 3072, 4096 bits.
DSA (Digital Signature Algorithm)
Key Sizes: 1024, 2048, 3072 bits.
ECC (Elliptic Curve Cryptography)
Key Sizes: 160, 224, 256, 384, 521 bits.
DH (Diffie-Hellman)
Key Sizes: 2048, 3072, 4096 bits.
MD5 (Message Digest Algorithm 5)
Digest Size: 128 bits.
SHA-1 (Secure Hash Algorithm 1)
Digest Size: 160 bits.
SHA-2 (Secure Hash Algorithm 2)
Digest Sizes: 224, 256, 384, 512 bits.
SHA-3 (Secure Hash Algorithm 3)
Digest Sizes: 224, 256, 384, 512 bits.
Definition: X.509 is a standard defining the format of public key certificates. Certificates are used in various security protocols to authenticate identities.
Components:
Subject: Entity the certificate represents.
Issuer: Entity that issued the certificate.
Public Key: Public key of the subject.
Validity Period: Timeframe in which the certificate is valid.
Signature: Digital signature of the issuer to verify authenticity.
Certificates: Digital documents that use public keys to verify identity and establish secure communication. They contain information about the entity, the public key, the issuer, and the validity period.
Keys: Secret key (symmetric) or public/private key pairs (asymmetric) used for encryption, decryption, signing, and verifying data.
Definition: A digital signature is a mathematical scheme for verifying the authenticity and integrity of a message, software, or digital document.
Usage:
Signing: The sender uses their private key to create a signature on a message.
Verification: The recipient uses the sender's public key to verify the signature and ensure the message was not altered.
Example: Signing a document with a private key in RSA, verifying it with the corresponding public key.
Master Key: Symmetric key used to derive/encrypt other keys.
Keypair: Asymmetric, includes a public key and a private key.
Public Key: Asymmetric, used for encryption/verification.
Private Key: Asymmetric, used for decryption/signing.
Secret Key: Symmetric, used for both encryption and decryption.
Write/Read Key: Can be symmetric or asymmetric, depending on the context.
Symmetric Algorithms: AES, DES, 3DES, Blowfish, Twofish.
Asymmetric Algorithms: RSA, DSA, ECC, DH.
Digest Types: MD5, SHA-1, SHA-2, SHA-3.
Certificate X.509: Standard for public key certificates.
Certificate vs. Keys: Certificates authenticate identities, keys are used for encryption/decryption.
Signature: Digital signatures ensure authenticity and integrity using private/public keys.