10 Cryptography Techniques for Secure E-Voting

Published on 7 August 2023 9 min read

Symmetric Key Cryptography
Public Key Cryptography
Hash Functions
Digital Signatures
Blind Signatures
Homomorphic Encryption
Zero Knowledge Proofs
Secret Sharing Schemes
Ring Signatures
Commitment Schemes

Picture this: it's election day, and you're casting your vote—not at your local polling station, but from the comfort of your own home, using your computer or smartphone. This is the world of electronic voting, a process that's made possible, in part, by cryptography. Cryptography, or the practice of securing communication, is a powerful tool when it comes to safeguarding our votes. It makes sure that no one can tamper with them and that everyone's voice is heard fairly. In this blog, we'll explore ten cryptography techniques that are key for secure electronic voting systems. So, get ready to dive into the fascinating world of digital codes and ciphers!

1. Symmetric Key Cryptography

Let's start with Symmetric Key Cryptography, also known as secret key cryptography. This is a method where the same key is used for both encryption and decryption. Think of it like a secret handshake: you and your friend know it, and you use it to recognize each other. Now, if you wanted to send a secret message to your friend, you'd use this secret handshake—or in our case, the secret key—to lock (encrypt) and unlock (decrypt) the message.

When it comes to cryptography for secure electronic voting systems, Symmetric Key Cryptography is a fundamental technique. Here's why:

Speed: It's faster than its counterpart—public key cryptography. This speed is important when dealing with the large volume of votes in an election.
Security: As long as the key remains secret, the votes are secure. This makes symmetric key cryptography a solid choice for maintaining the integrity of electronic votes.

However, it's important to note that Symmetric Key Cryptography isn't without its challenges. For instance, how do you securely share the secret key with all voters? And how do you ensure that only eligible voters receive the key? These are questions that election authorities must consider when using Symmetric Key Cryptography in electronic voting.

So, there you have it: Symmetric Key Cryptography—a core tool in the cryptography toolbox for secure electronic voting systems. Next time you hear about e-voting, remember the secret handshake!

2. Public Key Cryptography

Let's move on to another kind of cryptography that's commonly used in secure electronic voting systems: Public Key Cryptography. Now, you might be wondering, "What's that?" Well, let's think about it like this: imagine you have a mailbox with a slot where anyone can drop in mail, but only you have the key to open it. That's essentially how Public Key Cryptography works.

In Public Key Cryptography, two keys are used: one public, one private. The public key is like the mail slot—anyone can use it to encrypt a message. However, only the private key can decrypt the message. And just like your mailbox key, the private key is kept securely by the owner—meaning, in our case, the voter.

Here's why Public Key Cryptography is important for secure electronic voting systems:

Secrecy: The private key never needs to be shared, so there's less risk of a security breach. This makes Public Key Cryptography a good choice for keeping votes confidential.
Authenticity: Because the private key is unique to each voter, it can be used to verify the voter's identity. That way, we can be sure that each vote is legitimate.

Of course, as with any technology, Public Key Cryptography isn't perfect. For example, managing public keys can be complex, and there's always the risk that a private key could be lost or stolen. But with careful use, Public Key Cryptography can be an effective tool in the cryptography toolkit for secure electronic voting systems.

So, next time you're checking your mail, remember: that little key in your hand is a lot like the keys in Public Key Cryptography—keeping your messages secure and your identity safe!

3. Hash Functions

Have you ever played a guessing game where you give clues and others try to guess the answer? Well, Hash Functions in cryptography are somewhat like that. They transform input data (like a vote) into a fixed-size string of characters, which represents the 'fingerprint' of the data. No matter how many times you run the same data through a hash function, you'll always get the same fingerprint. But even a small change in the data will create a completely different fingerprint. Interesting, isn't it?

Here's an example: let's say you vote for 'Candidate A'. The hash function might turn that into something like '3e23bf3'. If you vote for 'Candidate B' instead, the hash might be '7f8e9d1'. The important thing is that you can't work backwards from the hash to figure out the original vote. This is what makes Hash Functions a key part of cryptography for secure electronic voting systems.

So, what makes Hash Functions valuable in secure electronic voting systems?

Integrity: If even a tiny part of a vote is changed, the hash will change too. This helps us to verify that votes haven't been tampered with.
Non-reversibility: As I mentioned, you can't work backwards from the hash to the original data. This keeps votes confidential, as no one can determine who you voted for based on your hash.

Hash Functions are like the secret sauce in the recipe for secure electronic voting systems. They might not be the main ingredient, but they add that extra kick that makes the whole dish come together. So next time you cast a vote, remember: a Hash Function is working hard in the background to keep your vote safe and secure!

4. Digital Signatures

Imagine you are sending a handwritten letter; you would usually sign it at the end, right? In the world of digital data, we do something similar. We use something called Digital Signatures. They are the digital equivalent of a handwritten signature or a stamped seal, but even more secure.

A Digital Signature is created using the sender's private key, which is like a unique digital fingerprint. It's like having a super special pen that only you can use to sign your name. This is a vital part of cryptography for secure electronic voting systems.

So, why do we need Digital Signatures in secure electronic voting systems? Here are a couple of reasons:

Authentication: Digital Signatures verify that the vote has come from a legit voter and not some sneaky imposter. It's like the bouncer checking your ID at the door of a club. Only in this case, the club is the voting system, and the ID is your Digital Signature.
Non-repudiation: This fancy term simply means that once you've cast your vote, you can't deny it later. It's like leaving a signed receipt after buying something; you can't claim you didn't make the purchase.

In conclusion, Digital Signatures are like the trusted guards of the secure electronic voting systems. They make sure each vote is genuine and traceable, without revealing who you voted for. That's pretty cool, right?

Now, let's talk about Blind Signatures. Sounds mysterious, right? Well, they're not as complicated as they sound. In the world of cryptography for secure electronic voting systems, they are super important.

Imagine you're sending a secret message in a sealed envelope and someone has to stamp it without opening it. That's kind of how Blind Signatures work. They allow a message to be signed without revealing its contents. It's like sending a secret vote without anyone knowing what's inside.

Blind Signatures play a critical role in secure electronic voting systems because they ensure the following:

Privacy: Your vote is your secret. Blind Signatures ensure that your vote stays anonymous. It's like voting behind a curtain; no one should know who you voted for.
Double-spending prevention: This term is borrowed from digital currency, but applies here too. Basically, it ensures that a vote can't be used more than once. It's like having a unique ticket for a show; once it's used, it can't be used again.

In summary, Blind Signatures play a key role in maintaining voter privacy while ensuring the integrity of the voting process. So, next time you vote electronically, remember the part Blind Signatures play in keeping your vote secret and safe.

6. Homomorphic Encryption

Ever heard of a magic trick in the world of cryptography for secure electronic voting systems? Well, let's introduce you to Homomorphic Encryption. It's a bit like a magic trick because it allows computations to be performed on data while it's still encrypted. Pretty neat, right?

But why is this technique important for secure electronic voting systems? Here's why:

Secrecy: Your vote is encrypted, which means it's turned into a secret code. And the best part? Even while counting votes, the encryption stays on. It's like having a secret ballot box that can be counted without ever being opened!
Verifiability: With Homomorphic Encryption, anyone can confirm that the votes were counted correctly without knowing the individual votes. It's like knowing the total number of apples sold at a market without knowing who bought them.

So next time you're casting your vote in an electronic system, just remember, Homomorphic Encryption is working behind the scenes. It ensures your vote is a secret, yet it counts towards the final tally. It's one of the clever cryptography techniques that keep our electronic voting systems secure and reliable.

7. Zero Knowledge Proofs

Imagine trying to convince your friend that you know the secret recipe to the world's best chocolate cake, but without giving away the actual recipe. Sounds impossible, right? Well, welcome to the world of Zero Knowledge Proofs.

In cryptography for secure electronic voting systems, Zero Knowledge Proofs work in a similar way. They allow you to prove that you have a certain piece of information, like a password, without revealing the information itself. It's a bit like saying, "I can prove I know the secret recipe by baking the world’s best chocolate cake, but I won't give you the recipe."

So why do we need Zero Knowledge Proofs in secure electronic voting systems? Here are a couple of reasons:

Privacy: You can prove you're eligible to vote without revealing your identity. It's like going to a masked ball, where you prove you received an invitation without removing your disguise.
Integrity: The voting system can verify your eligibility without knowing who you are. So, no more worries about someone snooping on your vote!

So, every time you vote, remember there's a lot of smart cryptography, like Zero Knowledge Proofs, working to keep your vote both secure and private. Now, isn't that a sweet piece of cake?

Did you ever share a secret with a friend when you were a kid? Maybe you each had a piece of a 'best friend' necklace, and only when you put them together could you read the whole message. Secret Sharing Schemes in cryptography for secure electronic voting systems work on a similar principle.

With Secret Sharing Schemes, a 'secret' (like the key to the voting system) is divided into parts. Each part alone doesn't tell you anything about the secret, but when you bring them all together—voila!—you get the full secret.

Why does this matter for secure electronic voting systems? Here's why:

Security: Even if someone gets their hands on one piece of the secret, it's useless without the rest. It's like only having half of your 'best friend' necklace. Without the other half, you can't read the message.
Collaboration: It encourages different parties to work together. To unlock the secret, all the pieces need to come together. So, it's like a team sport, where everyone has to play their part.

So, the next time you vote electronically, remember that there's a secret being shared behind the scenes, working to protect the integrity and security of your vote. And that's no secret anymore!

9. Ring Signatures

Imagine playing a game of 'who said it?' with your friends. You all write down a funny quote, mix them up, and try to guess who wrote what. But, here's the twist: the quotes are anonymous. Once they're mixed up, there's no way to tell who wrote what. This is the essence of Ring Signatures in cryptography for secure electronic voting systems.

Ring Signatures provide a way to sign a document (or in our case, a vote) anonymously. It's like leaving a footprint in the sand that says "a person was here," but you can't tell exactly who. Here's why this is important in electronic voting:

Anonymity: When you cast your vote, you don't want anyone to know it was you, right? Ring Signatures make sure your vote is counted, but they don't reveal your identity.
Authenticity: While keeping your vote anonymous, Ring Signatures also make sure it's valid. It's like having an invisible stamp of approval.

So, thanks to Ring Signatures, you can vote in peace knowing your vote is secure, valid, and most importantly—anonymous. And that's a win for democracy and cryptography for secure electronic voting systems!

10. Commitment Schemes

Think of a commitment scheme like a lock box for your secrets. You can put your secret in the box, lock it, and give it to someone else. They know you've committed to a secret, but they can't see what it is until you give them the key. Now, imagine that secret is your vote in an electronic voting system. That's exactly how Commitment Schemes work in cryptography for secure electronic voting systems.

Commitment Schemes have two main parts:

Commit Phase: This is when you cast your vote. Your vote is locked away in a cryptographic 'box'.
Reveal Phase: After all votes are cast, the 'box' is opened and the vote is counted.

This two-phase approach ensures two important things:

Secrecy: During the commit phase, no one can see your vote. It's like a secret ballot, but even more secure because it's protected by cryptography.
Immutability: Once you've cast your vote, you can't change it. This prevents tampering and makes sure each vote is final.

So, commitment schemes work like a digital lock box, keeping your vote safe and secure until it's time to be counted. And that's the final piece of the cryptography for secure electronic voting systems puzzle!

If you're intrigued by cryptography techniques and want to learn more about the backbone of the digital economy, check out the workshop 'Crypto For Creators, Part 1: The Backbone Of The Digital Economy' by Tom Glendinning. This workshop will provide you with a deeper understanding of cryptography and its applications in secure e-voting and other digital technologies.