cointelegraph

How to put words into a Bitcoin address? Here’s how vanity addresses work

Have you ever wondered whether a Bitcoin (BTC) address — or a string of 26–35 alphanumeric characters — can happen to have human-readable words instead of random letters?

You’ve probably heard of the Lightning Network, which allows you to create a fancy BTC address that looks like an email or a web domain. But there’s also a way of creating Bitcoin addresses containing human-readable words on the original Bitcoin blockchain. Such addresses are known as vanity Bitcoin addresses.

What is a vanity Bitcoin address?

A vanity Bitcoin address is a personalized BTC address that contains a specific pattern or word in a part of its total 26-35 character string of letters and numbers. Unlike a usual Bitcoin address — which is made of random characters — a vanity Bitcoin address allows users to customize their addresses or even send a specific message just within the address.

The term “vanity address” comes from the plain meaning of the word “vanity,” which is used to express inflated pride in oneself or one’s appearance. In line with the direct meaning, vanity addresses are used by those who want to stand out and give their wallet address a unique identity.

How to put words into a Bitcoin address? Here’s how vanity addresses work

Vanity Bitcoin addresses became popular a few years after the anonymous Bitcoin creator Satoshi Nakamoto launched the cryptocurrency back in 2009. The first vanity address generator, called “VanityGen,” was released as an open-source platform on GitHub in 2012. One of the first references to vanity addresses on Bitcointalk.org — a major crypto forum created by Nakamoto — goes back to 2013.

According to Trezor’s Bitcoin analyst Josef Tetek, Nakamoto didn’t use vanity addresses: “He disappeared from the public before vanity addresses became popular,” Tetek told Cointelegraph, referring to Nakamoto’s vanishing in 2011.

Besides the Bitcoin blockchain, vanity addresses are also available on other networks, including the Ethereum blockchain. Unlike Bitcoin vanity addresses, which allow users to choose among 26–35 alphanumeric characters, Ethereum vanity addresses only feature hexadecimal numbers, as Ether (ETH) addresses can only include letters “A” through “F” and numbers zero through nine.

According to the ETH Optimism vanity address generator, creating an Ethereum vanity address starting with “0xFad69” would take up to five minutes.

How to create a Bitcoin vanity address?

There are two ways of creating a vanity BTC address: manually and using specialized vanity address generator services. The first method relies on software and requires some computing power and coding skills to run programs to find Bitcoin addresses starting with a specific word combination.

Many Bitcoin experts like Trezor’s Tetek agree that the first method is the most secure way of creating a vanity Bitcoin address, as this method allows users to keep their seed phrase private. Being the only owner of a private key or a seed phrase enables the user to be the sole holder of the funds associated with the address.

The manual method requires installing vanity address-generating software like VanityGen, which is available on the cloud-based software website GitHub. Running such software requires certain computing power specs, with larger sequences of symbols demanding more time to create a vanity address.

Various sources estimate that generating a vanity address containing a five-symbol word takes about one hour using a regular personal computer, while larger sequences like seven symbols could take up to three months. More sophisticated setups involving powerful graphic cards or even application-specific integrated circuit (ASIC) chips can significantly reduce the time needed to generate a vanity address.

How to put words into a Bitcoin address? Here’s how vanity addresses work

The second method of creating a vanity address is more straightforward but less secure as it relies on delegating the address search to third-party services, also known as “vanity address miners.”

Reliance on Bitcoin vanity services is associated with major risks, as miners can potentially take over the address and its assets at any time. That is because such miners are the first to receive the private key before passing it to the customer. The private key is generated at the moment of creating a Bitcoin address and cannot be changed afterward.

The vanity generation service is often offered via websites like Vanitygen.net, allowing users to simply order a certain desired word or sequence to be searched with computing power bought online. Such services often allow users to order a sequence of letters up to eight symbols. Once generated, the private key for the vanity address is sent to the customer’s email in exchange for the agreed price.

For example, generating a Bitcoin vanity address starting with “1Satoshi…” would cost around 0.0217 BTC, worth around $600 at the time of writing. Larger sequences like “1Nakamoto…” would require at least 0.11 BTC, or as much as $3,250.

How to put words into a Bitcoin address? Here’s how vanity addresses work

It’s important to note that not all letters and numbers can be included in a vanity Bitcoin address, just like a normal BTC address. Some letters, like the uppercase letter for “O,” the uppercase letter for “I,” the lowercase letter for “L,” and the number “0,” are excluded from the set of 26–35 alphanumeric characters available in all Bitcoin addresses. The exclusions aim to help users avoid confusion when sending funds on the Bitcoin blockchain.

The risks of using a Bitcoin vanity address

A decision on whether or not to use a Bitcoin vanity address ultimately depends on the reasons for having such an address in the first place, taking into account all possible risks. Some cryptocurrency exchanges like BitMEX have experimented with vanity addresses using the native Segregated Witness (SegWit) address format Bech32 with the “bc1qmex…” prefix.

A spokesperson for BitMEX told Cointelegraph that most vanity addresses are used for marketing or considered “a bit of fun.”

“Bitcoin vanity addresses were quite popular on BitcoinTalk circa 2011, when many solicited donations to their personal vanity address, for example, 1Name,” the BitMEX’s representative noted, adding:

“In the days before structured proof of reserves systems, the exchange-wide use of vanity addresses gave a way for users to informally sum up the reserves of an exchange.”

The firm also attempted to use vanity addresses to make it harder for attackers to scam users since BitMEX only gave vanity addresses to users. However, one should not rely on vanity addresses as a security mechanism, as more advanced attackers could manage to copy the vanity address format, the representative noted.

BitMEX’s spokesperson says vanity addresses are best suited for advanced users: “The main weakness for individual users is reduced privacy. In general, we would advise users not to reuse addresses at all,” adding that newer BitMEX customer addresses no longer feature a vanity prefix.

Trezor’s Bitcoin expert Tetek strongly advised against using vanity addresses because such addresses — even if generated in a secure manner — promote address reuse, which is a bad practice in terms of privacy. He said:

“If a Bitcoin address is used more than once, other people can easily track the receiving and spending habits of a person. It is, therefore, also easier to identify the owner of the address.”

Besides privacy and asset safety risks, vanity BTC addresses are also associated with security vulnerabilities. In 2022, hackers managed to steal $3.3 million in crypto through a vulnerability in Ethereum vanity address-generating tool Profanity. Additionally, in March 2023, attackers also used hacked vanity addresses to steal $500,000 worth of tokens from layer-2 scaling solution Arbitrum’s airdrop.

The future of Bitcoin vanity addresses

Despite Bitcoin vanity addresses becoming much less popular since 2011, there is no evidence that such addresses have not been used in recent years.

One report recently described the use of a Bitcoin vanity address containing swearing words apparently directed toward Russia’s President Vladimir Putin. The address has transacted a total of 0.29 BTC ($7,595) in 67 transactions between 2018 and 2020, turning its balance to zero.

One of its last recorded transactions included a 0.0004 BTC ($10) transaction to the public Bitcoin address of famous Bitcoin critic Warren Buffet, who was given a BTC address and a gift from Tron founder Justin Sun.

Moreover, challenges and considerations persist. For instance, the security risks linked to vanity address generators must be addressed, prompting the development of more secure and user-friendly tools. Vanity address creation could become more streamlined and available to a wider audience, not just those with coding expertise, as blockchain systems develop and incorporate new features.

However, the privacy issues raised by the reuse of addresses will remain a crucial consideration. Therefore, users who want personalized addresses must balance the advantages of uniqueness against possible privacy breaches.

While it’s important to understand that Bitcoin vanity addresses are quite risky and expensive, such addresses apparently unlock some new and maybe weird use cases of the cryptocurrency. With that in mind, it’s up to Bitcoin users whether the future of Bitcoin vanity addresses is bright or not.