Digital Signature in Cyber Security

With all companies having a strong online presence and rising technology evolution, security is a major issue. Companies are dealing with sensitive information every day on the internet. This may be with the employees, clients, authorities, and practically all other stakeholders.

But Is it safe to do so? The answer is a clear no. Safety protocols are essential for maintaining the security of the information. A digital signature is one such technique to ensure a company’s safety in today’s world.

It is a method for validating the authenticity and integrity of any type of file. This is similar to handwritten signature or stamped seals but with more security features. It came in the frame with an aim to solve tampering and identity-related problems.

It is solid proof to authenticate origin, identity, transactions, and more. The senders and recipients, both benefit from this to ensure their safety and security. We will be looking at the digital signature and its application below –

Pretty Good Privacy and Public Key Infrastructure

The digital signature needs Public Key Infrastructure (PKI) and Pretty Good Privacy (PGP) to strengthen the security while transmitting public keys. They are essential to verify the sender’s identity and if the public key belongs to him.

The PKI has a set of protocols that studies the distribution of public keys and verifies the entity with the digital certificates. They are responsible for validating and managing public key certificates with the help of the certificate authority.

Pretty Good Privacy on the other hand follows the concept of Web of Trust. It connects different users who sign the certificates of verifiable identities. It uses symmetric key and public key cryptography to follow the authentication process.

Both are effective as long as the strength of the private key security is strong. They enable companies to identify a key and catch impersonating people.

Benefits of Digital Signatures

Security is the main reason why people use digital signatures. Some of the features that come with digital signatures are –

1. It provides personal identification numbers and codes that allow authentication of the signer’s identity and thus approval. This includes email, username, and passwords as the main methods.

2. Asymmetric cryptography is a method that uses a public key algorithm for encryption and authentication. Public key cryptography is another name for it.

The public key is for encryption of the message under this method. A private key is for decryption after the receipt gets the message. This is more reliable than symmetric keys which use the same key for encryption and decryption.

3. The checksum is a type of data fingerprint which allows the comparison of digital data to detect errors or changes.

4. Cyclic redundancy check allows error detection and verification in raw data stored in digital networks and storage devices.

5. Certificate authority validation is the issuing of digital signatures by verifying and accepting digital certificates, to avoid fake creation.

6. The trust service provider is responsible for validating the digital signature on behalf of a third party.

Some other benefits are –

1. It provides a timestamp by recording the time and date of the digital signature. This is very useful in emergency situations like stock trades and legal proceedings.

2. It saves time by removing the steps like physical storage and exchange, signing, etc.

3. It is very cost-effective as the company saves up on space, resources, and labor.

4. It also cust the physical waste generation and promotes a positive attitude.

5. They are easy to trace which makes maintaining a record easier.

Digital Signature Creation

There are two major steps in this process – signature and verification.

1. Signature

The digital signature creation needs to follow the one-way hash function for data to be signed. A hash is a fixed chain of numbers that comes from mathematical algorithms. It is unique to a file and irreversible even if another file generates the same hash value.

The creator then uses a private key to encrypt the hash which generates the digital signature. They only encrypt the hash and not the whole message because hashing takes less time than signing. The signer also attaches the developer’s certificate to authorize the signature.

2. Verification

Once the receipts get the file, he uses a decryption mechanism to decode the hash and the signature. This is done with the help of the sender’s public or private key. The decrypted hash must match the computed hash of the data to prove zero manipulation. In case of differences, the data is compromised or there is an authentication issue.

The steps involved in short are –

1. File selection for digital signature.
2. Hash calculation of the message using a private key of a sender.
3. Transmission of the original file along with the digital signature.
4. The decryption of a message by the sender using the public key of a sender.
5. The receiver gains computing access to the file.
6. Comparison of original computed file and decrypted file to ensure integrity.

Algorithms in Digital Signature

1. Key generation algorithm

It uses random sampling by picking a random private key from a set of keys. They are crucial to authenticate the sender’s identity. And to avoid data alteration by a third party acting as a sender.

2. Signing algorithm

A signing algorithm is responsible for producing document signatures. This uses a private key to encrypt hash value. After this, the data reaches the verifies for further process.

3. Signature verifying algorithm

A signature verifying algorithm is for checking the authenticity of a document. It applies the original hash function to compare the data and see if it is valid or not.

Application of Digital Signature

1. Authentication

It allows authentication of the message source and sender’s identity. This process allows verification of the user accessing the system.

2. Non-repudiation

Non-repudiation is a way to ensure that an entity does not deny the contacts’ authenticity and the origin of the signature.

3. Integrity

Integrity is for ensuring that the contract is accurate and original. It proves that the contract will not go under manipulation during the transmission.

Some of the real-world applications of digital signature are –

1. Email sender authentication
2. Document and certificate authentication
3. Software authentication

PKI digital Certificates using this signature commonly are –

1. Email signing certificates
2. Code signing certificates
3. SSL/TLS certificates

Classes of Digital Signatures

1. Class 1

They are not fit for legal business documents and receive validation solely on email ID and username. They offer only basic levels of security for low-risk data.

2. Class 2

These are common for the electronic filing of tax documents as they receive validation based on pre-verified databases. They offer tighter security for moderate-risk data and the environment.

4. Class 3

They offer the highest level of security because of stricter protocols. The person needs to prove his identity in front of certifying authority before signing. E-auctions, e-tendering, etc. use class 3 of the digital signature because threats are higher in these environments.

Types of Digital Signature

1. Certified Signatures

This signature has a unique blue ribbon at the document top with the name of the signer and issuer. These elements ensure that the document is authentic and safe.

2. Approval Signatures

These signatures are common for an organization’s business workflow as they speed up the approval process. It includes the official seal, date and location, and an image of the physical signature.

3. Visible Digital Signature

This signature enables the signing of a document digitally. The format of it is similar to a sign on a physical document.

4. Invisible Digital Signature

Here, only a blue ribbon in the taskbar is visible. This is when the company doesn’t want to use their signature, but they need to prove its authenticity and origin.

Uses of Digital Signature

1. Government Bodies

The government uses it for publishing confidential documents like budgets, tax returns, law bills, and contracts. They follow very strict protocols while using digital signatures like smart cards to ID the employees. Only these cardholders have access to the digital signature, securing the institution’s systems.

2. Banking Industry

The banking industry uses it for contracts, loan processes, mortgages, and many more documents. They need to follow the guidelines issued by E-Sign Act, Uniform Electronic Transactions Act, and the Federal Financial Institutions Examination Council.

3. Cryptocurrencies

Cryptocurrencies and bitcoin need the signature for blockchain authentication. This allows transaction data management as well as ownership of the currency.

4. Healthcare Sector

The Healthcare sector uses it for administrative processes, admissions, prescriptions, and strengthening data security. All the hospitals must abide by the guidelines in the Health Insurance Portability and Accountability Act of 1996.

5. Manufacturing Organisations

The manufacturing companies use to improve their efficiency by speeding up the processes. This includes product design, quality assurance, invoice, etc. The International Organization for Standardization, National Institute of Standards and Technology, and Digital Manufacturing Certificate are the monitoring bodies in the field.

Encryption with Digital Signature

Companies now prefer to use encrypted messages to maintain confidentiality. But in the case of PKI, identity spoofing has become quite common leading users to use PKC for encryption. This is done by combining digital signatures and encryption schemes.

Sign-then-encrypt and encrypt-then-sign are two ways of achieving this requirement. Sign-then-encrypt allows receivers to fake the identity of the sender and misuse the data. Thus the process of encrypt-then-sign is more reliable in terms of safety.

Digital Signature Tools

1. Zoho Sign

It is a digital signature app that works online to handle digital signatures legally. This manages the authenticity and timeliness of the digital signatures. It also offers custom branding options to its members.

2. Sign Request

Offering affordable digital signature service to over 500.000 users. It follows legal e-signature solutions in almost 26 countries and ensures authenticity and integrity all the time.

3. Eversign

This offers digital signature service with full guidance to all its clients. It is known for its high level security allowing companies to trust them with confidential information. It is also easy to use and allows small businesses to be part of the community as well.

Drawbacks of Digital Signature

The cost of the digital signature is an issue for many organizations. The public key encryption system needs constant support from the Certificate Authority which is very costly when a company needs thousands of digital signatures.

This is why companies are rooting for real-time encryption protocols and multi-factor authentication. Though they are not as good as digital signature systems, technology evolution can make them competent. Right now they are not compatible because the creator’s identity authentication is only possible with digital signatures.

Digital Certificate

A third party issues a digital certificate after verifying the sender’s identity and receiver’s identity to each other. The Certificate Authority issues this certificate in an encrypted form that has the public key and other important information. It contains –

1. Certificate holder name
2. The unique serial number for identification
3. Expiration date
4. Copy of certificate holder’s public key
5. Authority’s Digital Signature

Difference between Digital Certificate vs Digital Signature 

Difference between Electronic and Digital Signatures

Conclusion 

We saw how important role a digital signature plays in securing communication between two parties. And the use of this signature is likely to continue due to high-security features and lower complications.

With larger companies relying highly on that, many other small businesses are likely to follow. It is a secure way to deal with confidential information and not fall into a hacker’s trap. Having enough knowledge about it will only improve the process when you implement this security technique in real life.