Essential Digital Communication Security: A Guide for Product Managers
In the digital age, securing online communication is of utmost importance. As most of our personal, professional, and financial interactions occur over the internet, protecting the...
In the digital age, securing online communication is of utmost importance. As most of our personal, professional, and financial interactions occur over the internet, protecting the associated data is crucial. This blog post explores the significance of confidentiality, integrity, and authenticity in digital communications, and examines the techniques used to secure these communications, along with their benefits and limitations.
Confidentiality: ensures that information is accessible only to those authorised to have access. Encryption is a primary tool for maintaining confidentiality, transforming readable data into an unreadable format that can only be reverted by authorized parties.
Integrity: refers to the assurance that the information is trustworthy and accurate. Measures to protect integrity ensure that data has not been tampered with during transit.
Authenticity: is about verifying that the information comes from a legitimate source. It is crucial in establishing trust in digital communications.
Let’s delve deeper into the encryption techniques used in today’s digital era.
“Encryption is a technique to convert the plain text into Cipher text”
“Decryption is a technique to convert the cipher text back into Plain text”
Simple Encryption: Transform Plain text into Cipher text
In the scenario described above, where user X intends to send a message to user Y over the network:
User X utilizes a standard algorithm to encrypt the message, converting it from plain text to cipher text.
User Y subsequently employs the same encryption algorithm to decrypt the message, converting it from cipher text back to plain text.
Problem with simple encryption:
To talk to Z, X has to adopt a new encryption algorithm in order to avoid the risk that Z will decrypt the messages that are meant for Y using the existing encryption logic. One of the fundamental problems with basic encryption is its inability to scale up and also raising confidentiality concerns.
2. Key Based encryption: Uses industry vetted algorithms along with a unique secret key generated for each recipient.
Two types of key based of encryption:
Symmetric encryption : Encrypt and Decrypt using same keys
Asymmetric encryption : Encrypt and Decrypt using different keys
2a. Symmetric Encryption:
In Symmetric encryption, both the encryption and decryption processes use the same key.
User “X” generates a key, “K1,” and shares it with User “Y”.
User “X” encrypts the message using key “K1” and sends it over the network to User “Y,” who then decrypts the message using the same key.
Benefits:
Faster: Symmetric encryption algorithms are generally faster and more efficient than asymmetric algorithms. This makes them suitable for encrypting large amounts of data.
Low CPU cost: Symmetric encryption typically requires less computational power and memory, making it ideal for environments with limited resources.
Efficient Bulk Encryption: Symmetric encryption is well-suited for transferring large bulk data.
Drawbacks:
Less secure: The security of symmetric encryption relies on the secrecy of the key. If the key is compromised, all encrypted data is at risk.
Key distribution: The primary challenge with symmetric encryption is securely distributing the encryption key to all parties involved.
Conclusion:
While symmetric encryption is highly effective for ensuring confidentiality. But it has challenges when it comes to providing integrity and authenticity.
Issue with Integrity: Symmetric encryption transforms plaintext into cipher-text, but it does not include a mechanism to verify if the cipher text has been altered.
Issue with Authenticity: Since the same key is used for both encryption and decryption, anyone with access to the key can encrypt data. This makes it difficult to ascertain the identity of the sender, as any party with the key can generate a valid ciphertext.
2b.Asymmetric encryption:
Flow Understanding:
Key Generation: User “X” and User “Y” generate key pairs, consisting of a public key and a private key.
Public Key Distribution: User “Y” shares his public key with User “X”.
Message Encryption: User “X” uses User “Y” public key to encrypt a message.
Message Decryption: User “Y” uses his private key to decrypt the message.
Asymmetric encryption utilizes the RSA algorithm to create a pair of keys known as the Private Key and Public Key.
The purpose of Public Key is to encrypt data, while only the mathematically linked Private Key can decrypt that same data.
When someone wants to send a secure message to the owner of the key pair, they use the recipient’s public key to encrypt the message. Once encrypted, only the corresponding private key can decrypt the message.
Even if you have someone else’s public key, you cannot derive their private key. For instance, User X can encrypt a message using User Y’s public key, but only Person Y can decrypt it using their private key, which is kept secret and not shared.
Benefits:
Confidentiality: Public and Private keys are mathematically linked, but it is computationally infeasible to derive the private key from the public key. Only the owner of the private key can decrypt the messages, ensuring confidentiality.
Scalability: In large-scale environments, asymmetric encryption is more scalable than symmetric encryption. Each user only needs a single key pair (public and private key), reducing the complexity of key management.
Drawbacks:
Asymmetric encryption is generally slower and more computationally intensive than symmetric encryption.
Asymmetric encryption algorithms like RSA produce a fixed size of encrypted text based on the key size, regardless of the plaintext size within certain limits.
Due to the small block size, asymmetric encryption is not suitable for encrypting large amounts of data directly.
Asymmetric encryption provides:
Confidentiality: By encrypting data with the recipient’s public key.
Integrity: By using digital signatures to ensure the data hasn’t been altered.
Authenticity: By verifying the sender’s identity through digital signatures and public key verification.
Hybrid encryption:
Due to performance issues, asymmetric encryption is often used in combination with symmetric encryption (a hybrid approach). Asymmetric encryption is used to securely exchange a symmetric key, which is then used for the bulk encryption of data. This is called Hybrid encryption.
Hybrid encryption
A symmetric key is generated for encrypting the actual data.
This symmetric key is then encrypted using the recipient’s public key.
The encrypted symmetric key and the symmetrically encrypted data are sent together to the recipient.
The recipient first uses their private key to decrypt the symmetric key, and then uses the symmetric key to decrypt the data.
This hybrid method combines the efficiency of symmetric encryption for handling large data sizes with the security of asymmetric encryption for key exchange.