The Fundamental Guide to Types of User Authentication for Startups

Types of User Authentication

In an ever-busy digital atmosphere, the security of user credentials comes first on the list of entrepreneurs, organizations, and everything.

User authentication acts as the first barrier of protection to authorize only the proper users who can access sensitive data and operations on the system.

In any case, if there are different methods of authentication on the market, this can be challenging for entrepreneurs trying to find the best method.

There can be an even bigger range of alternatives, starting from a password-based one to the latest biometric and multi-factor identification methods.

This comprehensive article is an attempt to unveil the types of user authentication for startups by pointing out certain authentication systems’ strengths and weaknesses, and implementation issues.Knowing the complexities of each authentication option helps startups to make informed decisions on queries like how to secure mobile apps, how to improve mobile app performance, the streamlining of user experiences, and the relation of the users’ trust.

What is User Authentication?

User authentication is the verification of the identity of users who are trying to access a system, application, or digital resource. It assures that only permitted users may get access while putting off unauthorized users or malicious intentions.

Authentication most often involves a user presenting credentials, which are then verified by its system through records stored or through external authentication services.

The end goal of user authentication is to prevent unauthorized access to confidential data, services, or capabilities.

This can be accomplished by confirming the authenticated users by various means including passwords, unique biological characteristics (e.g., fingerprint, facial recognition), tokens, or a combination of these elements (i.e., multi-factor authentication).

Authentication of the user is a crucial step in cybersecurity for startups and businesses as it provides the first barrier against unauthorized access, data privacy, and other security threats.

Via strong authentication protocols, startups can protect the network with their cyber assets, shield user privacy, and build trust across their customer base.

Passwords Best Practices in the Real World

In the real digital world, the most effective way for startups and companies to boost security is to practice password best practices. These are some real-life examples of how to develop and keep passwords safe.

Use Strong, Unique Passwords: Encourage passwords that consist of letters (both upper and lowercase), digits, as well as special characters. Implement uncommon words and give every news account its very own password to prevent hacking if one is cracked.

Implement Multi-Factor Authentication (MFA): Incorporate an extra protective layer of MFA, a combination of a password with something the user has or is, for example, a one-time passwords or biometric data. MFA strengthens security with multiple authentication requests.

Educate Users About Phishing Risks: Teach users how to spot phishing emails that are designed to trick them and steal their login details. Teach them to double-check the requests before sharing private data.

Regularly Update Passwords: Cheer on the password modification every three to six months to reduce unauthorized access. Instill this policy with a password expiration rule.

Use a Secure Password Manager: Suggest using well-known password managers for safe storage and design of different passwords. They effortlessly deal with having different passwords for various accounts and, of course, follow the recommended practices.

Why is Securing User Authentication So Important?

Ensuring user authentication is paramount both for startups and businesses of which, some vital issues are illustrated as follows. Promoting strong authentication mechanisms is the way to improve general cybersecurity levels and build confidence in customers.

Protection of Sensitive Data

User authentication plays a role as the primary security obstacle hindering unauthorized access to valuable information which includes personal data, financial records, and proprietary business data.

Putting in adequate authentication mechanisms will prevent malicious actors from taking advantage of the escape routes and gaining unauthorized access which consequently could lead to data breaches.

Prevention of Unauthorized Access

Pirate digital resources may result in various security problems such as data leakage, identity theft, fraud, fraud, and system misuse among others.

Providing users with secure authentication means that only those who are allowed can use critical systems, applications, and services thereby lessening the chances of unauthorized activities and the dangers associated with them.

Compliance Requirements

Many branches of business have a requirement of regulatory rules and compliance norms related to the protection of personal data and privacy.

By enforcing a secure authentication method, companies can adhere to data privacy regulations such as GDPR (General Data Protection Regulation), HIPAA (Health Insurance Portability and Accountability Act), and PCI DSS (Payment Card Industry Data Security Standard), avoiding fines and reputation damage.

Safeguarding Business Reputation

An info leak because of weak authentication can ruin the company’s reputation and impair customers’ trust.

A recognition of authentication security by businesses shows their dedication to users’ privacy and security, an increment to their reputation, and customers’ trust in their services.

Mitigation of Financial Losses

The cost of data breaches and unauthorized access to the data could be hefty and can amount to thousands in fines, law settlement, recovery of data, and damage control.

Effective user authentication can prevent security breaches and minimize financial losses as well as business disruption.

Different Types of User Authentication

Combining our discussion around various authentication systems and their strengths, weaknesses, and implementation challenges, organizations can make better decisions toward securing their environments and the user’s identities.

1. Password Authentication

The most widespread way to identify users when they attempt to access digital resources like applications and websites, is via password-based authentication.

Password Authentication

Source: https://utlas.net/

User Input: Users type in their unique identifiers, such as usernames or emails and a password.

Verification Process: The system validates the credentials against the stored records. If they match, it will give permission.

Authentication Decision: Good verification means you can log in, otherwise, the options for password recovery will be available.


Familiarity: Passwords are the passwords understood and user-friendly memory of those.

Simplicity: Deploying password-based authentication is simple and does not require complicated technical overhead.

Accessibility: Users can log in from any device as long as they have an internet connection.


Password-related attacks: The use of passwords faces different threats to security such as brute force attacks, dictionary attacks, phishing, and password guessing.

User behavior: The users might select passwords of low strength, reuse them across multiple accounts, or share, which, in turn, enhances the chance of compromise.

Credential theft: By proxy, passwords can be intercepted in the transmission or stored insecurely, resulting in authentication that can be bypassed by attackers if they gain access to the authentication database.

My Assessment

Password-only authentication poses a high degree of risk in situations related to the data type such as finance or health. Yes, it may be sufficient for new startups with the slightest web presence and without any significant amount of user data. However, it is just a short-term measure.

The implementation of password-based authentication should be supported by widespread user training on password hygiene and the compulsory enforcement of password rules. Despite all the precautions, some risks remain indispensable.To minimize the risk, it is vitally important to perform regular security audits, which involve checking the compromised passwords through platforms such as ‘Have I Been Pwned’. This preventive approach will help detect weaknesses and will ensure that the entire perimeter is more secure.

2. Two-Factor Authentication (2FA)

“Two-factor authentication” (2FA) is a security solution that adds another layer of authorization and verification beyond the typical username-password combination.

Implementation of the 2FA makes users go through two different forms of verification before they are allowed to get access to a system, network, or service.

Two-Factor Authentication (2FA)

Source: https://doubleoctopus.com/

The following illustrates the 2FA process

First Factor (Knowledge): The users type in their username and password to the system which authenticates them.

Second Factor (Possession or Inherence): Thereafter, customers undergo a different method of authentication.

Authentication Decision: Upon interface, both factors confirm user identity for access.


Enhanced Security: Through the implementation of two levels of authentication, 2FA substantially lowers the possibility of unauthorized access even when just one factor (for instance, password) might be compromised.

Protection Against Phishing: 2FA guards the users against falling to phishing attacks for such attackers would require more than the user’s password to gain access.

Improved Compliance: Sometimes, statutory requirements or recommendations stipulate the use of 2FA to improve security and protect confidential data.


Usability Challenges: Furthermore, two-factor authentication can annoy users with extra steps that can turn into tedious processes, for example, retrieving physical tokens or waiting for an SMS code.

Dependency on Second Factor: The effectiveness of 2FA depends mainly on the reliability of the second factor; if this second factor is compromised or lost, the user can lose access, and methods for full recovery and backup should be readily available.

Costs and Complexity: Implementation and sustaining the 2FA procedure may result in extra costs, especially if the hardware tokens or biometric devices are used, and such systems may require the allocation of significant time, resources, and user training to be integrated.

My assessment

In the review section, I discovered that Two-factor Authentication works as a perfect entry point for startups as it strikes a balance between security and usability. The solution provides a way to achieve the required level of security while keeping the process of user authentication as simple as possible.

Also, 2FA is affordable, one can download authenticator apps free of charge and SMS-based solutions have costs lower than the benefits they offer.

For 2FA to be a better framework, startups should put users’ education first, emphasizing user contact and supporting users during the setup process.

3. Multi-Factor Authentication (MFA)

Multiple-factor authentication (MFA) is a security feature that requires users to verify two or more factors before accessing a system, application, or service.

As opposed to the conventional authentication methods which solely depend on passwords, MFA adds more security factors that combine several authentication methods typically from the following categories.

Multi-Factor Authentication (MFA)

Source: https://www.akamai.com/

Knowledge Factor: For example, something the user already knows, such as a password, PIN, or a personal security question.

Possession Factor: For example, something the user carries, such as a smartphone, hardware token, or smart card.

Inherence Factor: behavioral biometrics data that they are, like fingerprint, face, or iris recognition.

The MFA requires process usually consists of the following stages.

User Input: The client side gives the first authentication factor which is normally a password or a username.

Additional Authentication: The users are prompted to provide one or more extra authentication factors, such as entering a special code or scanning a fingerprint.

Authentication Decision: The system validates the entire given data. If they are equal, access is provided, if otherwise access is denied.


Increased Security: By combining multiple modes of authentication, MFA contributes to the reduction of the possibility of unauthorized access and the strengthening of security as well.

Protection Against Credential Theft: The fact remains that even in the case where only one factor, like a password, is hacked, the attackers still need to steal the other factors to succeed.

Compliance with Regulations: Most of the regulatory norms, for example in GDPR and PCI DSS, call for or advocate the use of MFA to strengthen security and protect confidential data.


Complexity: MFA can irritate users due to the additional steps, which is rather bothersome.

Dependency: MFA employs additional specifications like smartphones; if they are lost. access problems arise.

Costs: Applying MFA involves costly hardware like tokens.

My Assessment

In my opinion, among startups managing critical data, including financial or health records, adding Multi-Factor Authentication (MFA) is the most evident security feature.

Focus on the user experience by investing in MFA solutions that make login processes easy and hence reduce user drop-off.

The implementation of MFA would be phased beginning with targeting high-risk accounts such as admins and those with sensitive data access, and proceed from here if need be.

4. Biometric Authentication

Biometric Authentication refers to the use of unique physical or behavioral characteristics for individual user  identity verification purposes. These attributes may include fingerprints, facial features, iris patterns, voice prints, or even typing models.

How it works?

Enrollment: Take the person’s biometric data and keep it safe.

Authentication Process: Take biometric data and feed it into the system.

Feature Extraction: Get one-of-a-kind attributes from the biometric data.

Matching: The extracted features can now be compared with existing biometric templates.

Decision: Decide if the data captured is identical or differs from the stored template.

Access Granted or Denied: Conduct authentication and grant or deny access according to the authentication decision.

Biometric Authentication


Enhanced Security: Biometric data is practically not duplicable and hence is less vulnerable as compared to traditional authentication methods such as passwords or PINs.

Convenience: On the contrary, users no longer need to memorize or input passwords, thus authentication becomes easier and more friendly for the user.

Reduced Fraud: Because biometric data is distinctive to an individual, it lowers the chance of fraudulent operations like identity theft, or impersonation.


Privacy Concerns: Possessing and keeping biometric data involves the issue of privacy, as it requires access and storage of delicate personal information. There is a danger of unauthorized data access or inappropriate application.

Accuracy Issues: Biometric systems might experience problems with accuracy due to factors such as environmental conditions, natural changes in biometric traits over time, or false rejections/acceptance of biometric IDs.

Cost: Organizations that want to adopt biometric authentication systems may face high costs due to the need for specialized hardware as well as software.

My Assessment

In my opinion, biometrics are appropriate for startup companies that put user experience at the center of their business strategy, since they streamline the authentication process. Nevertheless, we should scale the security requirements against costs, especially when dealing with protected information.

When selecting biometric authentication providers, choose organizations with a demonstrated history of security. Crossing the t’s and dotting the i’s when it comes to how biometric data is stored and protected must be done to overcome the privacy concerns of users.

5. Token Authentication

A token-based authentication is an authentication method whereby unique tokens are used for authentication purposes instead of traditional usernames and passwords.

These tokens are emitted by an authentication server and they are mostly ephemeral which means they offer a means of security and a temporary way to verify a user’s identity. 

Token Authentication

How does it work?

During the authentication process, users supply their credentials to the authentication server. When access is granted, the server creates a unique token that is connected to the user’s session or account, respectively.

This token is secure is transmitted back from the user’s device and is safely saved in a cookie or local storage. The user will then provide the token in a request header or as a parameter when requesting access to the protected resource or service.

Then the server uses the token to check if it is valid and unexpired from his recording. In case the token is verified and the expiration date is not reached, users are granted access to the intended resource.


Enhanced Security: Tokens have a short life and randomly generated numbers which make it more difficult to reach the transaction if a hacker intercepts the message.

Statelessness: Token-based authentication is stateless, hence servers do not store session data between sessions. This makes it easier for servers to scale and manage.

Cross-Origin Resource Sharing (CORS) Support: The transferability of the tokens makes the implementation easier in various domains, which is why distributed systems and APIs can be smoothly authenticated.

Reduced CSRF Vulnerability: Platform tokens are stored on the client end and not automatically included in requests. As a result, they reduce the risk of Cross-Site Request Forgery (CSRF) attacks.


Token Management Overhead: Token lifetime, expiration, and revocation can be a complex part of the authentication.

Token Storage Risks: Although the client-side token storage could be vulnerable if applied properly, it could lead to token theft or misuse.

Token Transmission Security: The transmission of tokens privately over networks is equally important to prevent network disruptions due to malicious activities.

My Assessment

Of all the authentication methods, token-based authentication is the best for startups who depend heavily on API, as it can give them robust security and a simple process for access control.

Implementing tokens securely involves paying close attention to the code quality, defining security measures for developers, and, when necessitated, using specialized libraries.

While choosing the tokens, it is necessary to bring to attention the pros and cons of each of the tokens. Although JWTs (JSON Web Tokens) won the battle for standard, there might be alternative token types that better fit the unique security and operational requirements for specific applications.

6. Single Sign-On

The single sign-on SSO saves the user faced with authentication of multiple related applications or services.

Following their initial login with a trusted identity provider (IdP), the users get access to the authorized resources effortlessly and without having to re-enter their credentials every time they want to access a protected entry point.

SSO was popularized in the corporate world and cloud-native application development (SaaS).

Single Sign On

How it Works

At the initiation stage of authentication, users key in their credentials to the authentication server. Upon authentication, a server creates a token or session identifier and links it with the user’s session.

This token or identifier is safely transmitted to the client device where it is stored, usually, this is done in a cookie or local storage. For the following SSO environment access, users are already authenticated using the previously issued token or session identifier without the need for further authentication.

The server of authentication may cancel or invalidate the token or identifier if any changes in the security rules occur, e.g. if the user logs out or their session is expired.


Simplifies Login: SSO eliminates the need for users to have separate passwords for different apps by allowing the use of a single set of credentials for accessing multiple apps.

Enhances Security: Centralized authentication and authorization controls can be handled in such a manner that they will reduce the possibilities of password-related insecurities like weak passwords or password reuse.

Increases Productivity: SSO enables and simplifies the way people access apps and services, helping them save time both as users and IT admins, and leading to productivity growth.


Single Point of Failure: SSO increases the likelihood of having a single point of failure where such breaches or outages would affect users’ capability to gain access to several applications or services.

Complex Implementation: The issue of interlacing SSO with the existing identity and access management systems can be quite complex and time-consuming, especially in organizations that have old infrastructure.

Compatibility Issues: SSO may not smoothly integrate with all applications or services, whereas customization and development will be required to ensure compatibility due to the possibility of it not integrating with all applications or services

My Assessment

SSO becomes more significant as your business expands by adding more and more services and tools that your users would need access to.

When looking for an SSO provider, weigh the options between the providers, paying special attention to price and the range of features that match your needs.

Strike a balance between your security considerations and the size and complexity of your company. Early-stage startups may opt to delay full SSO establishment.

7. Certificate-Based Authentication

Certificate-based authentication (CBA) robustly incorporates digital certificates to verify user or device identity.

These digital certificates that are similar to digital passports can be issued by the Certificate Authorities (CAs) who attach a public key to identity using a cryptographic security mechanism.

To access, a user needs both the certificate and its private key. The latter is normally kept in a secure place.

How it works?

Users or devices obtain digital certificates from a trusted Authorized Certificate (CA), which contains a public key and user identification information. These certificates are very secure because they are either saved on the user’s device or hidden inside its hardware.

The user’s device offers first its digital certificate to the server when it attempts to access a secure resource or service. The server ensures the certificate’s validity by checking its digital signature against the CA’s public key.

Once a check is performed, if the certification complies with the authentication of the user’s identity and is validated, access to the resource/service is permitted.

Certificate-Based Authentication

Source: https://www.yubico.com/


Strong Security: Certificate-based authentication offers high-grade security as it relies on digital certificates, which are virtually impossible to fake or alter.

Mutual Authentication: It helps in establishing bidirectional authentication, through which the client and the server both authenticate each other which further improves security.

No Passwords: Users don’t need to memorize passwords, improving password security, as password-related vulnerabilities such as weak passwords or password reuse are reduced.


Certificate Management: The administration of digital certificates, that is, issuing, renewing, and revoking them, is a demanding task that requires methodology and personnel to be allocated.

Cost: Setting up and running a certificate infrastructure, comprising of acquiring the certificates from the trusted CAs, may cause financial loss.

Compatibility: Sometimes only legacy systems or devices will not support Certificate-based authentication.

My Assessment

Being a technical head in a leading social media app development company, I feel certificate-based authentication (CBA) is only good for some start-ups because of its costs and complexity unless compliance imposes that.

By contrast, startups operating in strictly regulated sectors like finance, government, or healthcare, working with high-security data, may have to implement CBA by regulation to meet their safety requirements.

Unlike the others, in this scenario, you should think more of CBA for specific, high-risk actions like administrative access or big transactions as opposed to using it for all processes.

8. Behavioral Authentication

Behavioral authentication implies an authentication by analyzing the patterns of behavior and activities to verify whether a person has a true identity.

Unlike the standard verification approach that relies solely on traditional credentials, it analyzes how users use and interact with digital systems by establishing some parameters like typing patterns, mouse movements, device usage habits, and navigation behavior.

Behavioral Authentication

Source: https://inte.finance.arvato.com/


Enhanced Security: While behavioral authentication can be a very effective method to secure data, it adds one more stage to the authentication process, thus, making it quite difficult for unauthorized users to log in.

Continuous Authentication: In contrast to static authentication ways like passwords, behavioral authentication never stops monitoring user behavior throughout the session.

User-Friendly: The behavioral authentication system is user-friendly as it does not require additional effort or input and can be easily integrated into customers’ daily activities, therefore making the user experience better.


Privacy Concerns: Gathering and analyzing behavioral data might be a cause of discomfort for users who don’t feel comfortable with the situation of their ongoing monitoring of activities and habits.

Limited Accuracy: Occasionally behavioral authentication systems may misjudge which one is a legitimate user versus an imposter, compromising their efficacy if a false negative happens.

Implementation Complexity: Carrying out behavioral authentication methods may develop to be a complex task and thus require a lot of resources in development, integration, and maintenance, especially for enterprises having sizeable user bases and various digital systems.

My Assessment

Behavioral authentication is most effective in security scenarios when it is used as a supplementary method along with other authentication methods, and not as the only security feature.

Nevertheless, it is a necessity for startups that they need to strike a delicate balance between the security merits of behavioral authentication and user privacy issues.

Through the introduction of intelligent systems, which will reduce the inaccuracy of blocking, startups can boost both security and user experience in their authentication processes.

9. Passwordless Authentication

Passwordless authentication is a kind of verifying a user’s identity that does not require a person to enter a traditional password. Rather than that it uses other authentication agents such as biometrics, one-time codes sent via email or SMS, hardware tokens, or cryptographic keys.

Passwordless Authentication

Source: https://www.strongdm.com/


Enhanced Security: Passwordless authentication considerably minimizes password security-related risks like password weaknesses, reuse passwords, and phishing by removing the need to create and recall passwords by users.

User Convenience: However, the absence of passwords leads to a simplified and efficient login process, resulting in enhanced user experience and reduced authentication friction.

Reduced Support Costs: One important benefit that passwordless authentication can provide is the reduction of the support costs associated with password resets and account lockouts as users no longer require the processing of password changes and resets.


Dependency on Alternative Factors: Passwordless authentication makes use of biometrics or hardware token technology, which could be either unavailable or incompatible universally.

Limited Adoption: Though they provide numerous advantages, there aren’t many applications that support them, and not all devices can use them, limiting the environment in which they can be used.

Security Risks of Alternative Factors: Password risks may be decreased by biometrics or one-time codes, hence there will be vulnerabilities like spoofing or interception.

My Assessment

Passwordless authentication suits startups by providing a great deal of balance of security properties and a hassle-free user experience.

For the successful integration of passwordless authentication, you need to carry out the analysis of the sensitivity of the data which includes the costs and complexities of various types of passwordless solutions.


The authentication solutions referred to here are part of our decades-long software development process and they have been used in several projects possessing different needs. Choosing the correct authentication method for your business model is cardinal.

If you need any help in choosing a product that suits your requirements or have any questions, do not hesitate to contact me or the customer support team.

Additional Resources

Starting as an iOS developer and moving up to lead a mobile team at a startup, I've expanded my expertise into Project Management, DevOps and eventually becoming a COO in the IT sector. As a COO, I excel in team leadership, technical advice, and managing complex business functions, focusing on combining technology and operations to drive growth. I'm keen to connect for collaborations or to exchange insights in the tech world!



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