In this lesson,
we will learn about Encryption Techniques.
Encryption techniques encompass the methods
and algorithms used to convert plain text into ciphertext
to protect data from unauthorized access.
Encryption techniques include Authenticated Encryption
with Associated Data, or AEAD,
and envelope encryption.
AEAD is an encryption technique
that simultaneously provides confidentiality, integrity,
and authenticity for both the encrypted message
and additional associated data.
Envelope encryption involves using a data key
to encrypt data and then encrypting that data key
with a master key.
Let's learn more about Authenticated Encryption
with Associated Data, or AEAD,
and envelope encryption.
First, we have Authenticated Encryption
with Associated Data, or AEAD.
AEAD is a type of encryption
that not only keeps data private,
but also ensures that it hasn't been tampered with
and comes from a legitimate source.
AEAD can validate both the encrypted data
and associated data known as additional
authenticated data AD, which is not encrypted,
but still needs protection against unauthorized changes.
Think of AEAD like sending a secure package.
The package itself is sealed to keep its contents private.
That's the encrypted data.
While the label, which holds important information remains
visible, but protected from changes,
that's the associated data.
If anyone tries to alter the package or the label,
a special security seal,
much like an authentication tag, would break
and alert the receiver that something went wrong.
In this way, AEAD ensures both the package
and its label arrived in act and authentic.
To achieve AEAD, enhanced encryption modes
like the Advanced Encryption Standard
in the Galois Counter Mode,
or AESGCM, are used.
These allow the associated data to be bound
to the encrypted message, ensuring any misuse
or alteration can be detected and then rejected.
AEAD encryption uses four inputs,
a secret key, a nonce or initialization vector,
the plaintext to be encrypted,
and the optional authenticated data.
A nonce, or initialization vector in AEAD is a
unique and random value used only once
to ensure that the encryption process produces different
ciphertexts, even when the same plaintext
and key are used.
With its four inputs, the AEAD algorithm then produces
ciphertext which keeps the data confidential
and provides an authentication tag
to verify the authenticity and integrity of the data.
When the data reaches its destination,
the receiver uses this tag to confirm
that the message has not been altered.
As you can see, AEAD goes beyond basic encryption
by adding essential checks for integrity
and authenticity, making it a strong choice
for secure data transmission.
Second, we have envelope encryption.
Envelope Encryption is a method of protecting data
by using two layers of encryption.
First, a data key is used to encrypt the data itself,
ensuring that the information is kept confidential
and secure.
This data key is then encrypted with a stronger master key,
adding an extra layer of security.
This is the envelope.
The master key is usually managed separately,
often using an asymmetric encryption algorithm like RSA,
which uses a public and private key pair
for added protection.
Think of envelope encryption,
like locking up valuable items in a box
and then putting that box inside a safe.
The data key acts like the lock on the box,
keeping the data safe inside.
The master key is like the physical safe
that holds the box, providing another layer of security.
This approach is commonly used in cloud services
and secure applications where managing
and protecting encryption keys is critical.
For example, in a secure messaging app,
envelope encryption ensures that the message is protected
by the data key,
while the master key protects the data key itself.
This two-step process ensures that both the data
and the keys that secure it are well protected,
making it much harder for unauthorized parties
to gain access to sensitive information.
Envelope encryption makes it easier to manage security
because the data key can be changed frequently without
having to update the master key.
This flexibility adds to its appeal as it allows
for frequent updates to data security measures
without compromising overall protection.
So remember, encryption techniques use various methods
and algorithms to convert readable data
into unreadable cipher text,
protecting it from unauthorized access.
authenticated Encryption with Associated Data, or AEAD,
not only encrypts the data,
but also includes integrity checks, verifying that the data
and any associated information like headers
or metadata haven't been tampered with.
This dual layer protection ensures
that both the encrypted message
and the associated data are secure and authentic.
Next, envelope encryption adds an extra layer of protection
by encrypting data with a data key
and then securing that key with a master key.
This layered approach helps safeguard both the data
and the keys themselves.
These techniques enhance data security
by ensuring confidentiality, integrity,
and authenticity, making them very important
for protecting sensitive information.